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==''[http://oeis.org The On-Line Encyclopedia of Integer Sequences]®'' of Neil Sloane et al.==
==''[http://oeis.org The On-Line Encyclopedia of Integer Sequences]®'' of Neil Sloane et al.==
* ''A Handbook of Integer Sequences'' (Academic Press, New York and London 1973).
* ''A Handbook of Integer Sequences'', N. J. A. Sloane, Academic Press, New York and London, 1973.
* Automatic detection and correction of invalid hyperlinks in the OEIS in 2008-2009
* ''[https://oeis.org/wiki/The_Encyclopedia_of_Integer_Sequences The_Encyclopedia_of_Integer_Sequences]'', N. J. A. Sloane and S. Plouffe, Academic Press, San Diego, 1995, 587 pp. ISBN 0-12-558630-2.
===Groups of sequences implemented for [https://github.com/archmageirvine/joeis jOEIS]===
* '''[[OEIS/morfix|morfix]]''', fixed points of morphisms
* '''[[OEIS/squaredig|squaredig]]''', numbers which have a subset of digits in the number and its square
===Small projects===
Cf. my [https://oeis.org/wiki/User:Georg_Fischer OEIS wiki user page]
* '''[[OEIS/coors|Coordination sequences for k-uniform tilings]]''' of Brian Galebach
* '''[[OEIS/B-file_check|B-file check]]''', initiated by Martin Pedersen
* '''[[OEIS/Broken_Links|Broken links]]''' detection and repair
* '''[https://oeis.org/wiki/User:Georg_Fischer/Coincidences Coincidences]''' - search lists for sequences with common terms
* '''[[OEIS/DFSA|DFSA]] Deterministic finite state automata for the enumeration of arrays with conditions
* '''[http://www.teherba.org/trottermath.net WTM]''' World of Terrel Trotter's Math (archive copy of the original webpage of 2004, c.f. his [https://oeis.org/wiki/User:Terrel_Trotter,_Jr. OEIS user page])
* '''[[OEIS/Engel_expansion|Engel expansion]]''' - English translation of Friedrich Engel's speech: ''Entwicklung der Zahlen nach Stammbrüchen.'' Verhandlungen der 52.
* '''[[OEIS/Eta_products|Eta products]]''' Dedekind eta, Jacobi theta_m, Ramanujan phi, psi, chi, f, a
* '''[[OEIS/Generating_Functions_and_Recurrences|Generating Functions and Recurrences]]'''
* '''[[OEIS/Holonomic_Project|Holonomic Project]]'''
* '''[[OEIS/Infinite_Products|Infinite Products]]'''
* '''[[OEIS/A220952|A220952]]''': 0, 1, 2, 3, 4, 9, 14, 19, 18, 17, 16, 11, 12, 13, ..., 49 ... by Donald E. Knuth, Feb. 20, 2013, was <code>unkn</code>, with additional '''[[OEIS/FASS_curves|FASS curves]]''': space-'''f'''illing, self-'''a'''voiding, '''s'''imple and self-'''s'''imilar curves
* '''[https://oeis.org/A131388 A131388]''', and [https://oeis.org/A131393 A131393] with recovered ''Rule 2'' and generalized '''[[OEIS/Negative-Positive|negative-positive]]''' incrementing sequences of Clark Kimberling, with listing and program
* '''[http://oeis.org/A030707 A030707]''', '''[http://oeis.org/A055187 A055187]''', '''[http://oeis.org/A217760 A217760]''' and related sequences, listing and program for generalized '''[[OEIS/Cumulative_counting|cumulative counting]]''', Clark Kimberling's [http://faculty.evansville.edu/ck6/integer/unsolved.html problem no. 4]
* '''[[OEIS/Triangles|Triangles with interlacing rows]]''', Clark Kimberling's [http://faculty.evansville.edu/ck6/integer/unsolved.html problem no. 18]; Perl and C programs find 1, 2, 20, 1744, 2 002 568, 42 263 042 752 triangles for the ''between'' condition


===Work on individual sequences===
===Individual sequences===
* '''[[OEIS/Triangles|Triangles with interlacing rows]]''', Clark Kimberling's [http://faculty.evansville.edu/ck6/integer/unsolved.html problem no. 18]
* '''[[OEIS/A003828|A003828]]''', Numbers n such that n^4 is a primitive sum of 3 positive fourth powers: 422481, 2813001, 8707481, 12197457, 16003017, 16430513, 20615673, 44310257, 68711097, 117112081, 145087793, 156646737, 589845921, 638523249, 873822121, 1259768473, 1679142729, 1787882337, 1871713857
* '''[[OEIS/A003828|A003828]]''', Numbers n such that n^4 is a primitive sum of 3 positive fourth powers: 422481, 2813001, 8707481, 12197457, 16003017, 16430513, 20615673, 44310257, 68711097, 117112081, 145087793, 156646737, 589845921, 638523249, 873822121, 1259768473, 1679142729, 1787882337, 1871713857
* '''[[OEIS/Negative-Positive|Negative-Positive]]''' incrementing sequences of Clark Kimberling, for example [https://oeis.org/A131388 A131388], and [https://oeis.org/A131393 A131393] with recovered Rule2
* '''[https://oeis.org/A035505 A035505]''', Kimberling's expulsion (shuffle) array [http://www.teherba.org/fasces/oeis/kea.html array visualization]
* '''[[OEIS/A220952|A220952]]''': 0, 1, 2, 3, 4, 9, 14, 19, 18, 17, 16, 11, 12, 13, ..., 49 ... by Don Knuth, Feb. 20, 2013 (nonn,unkn)
* '''[[OEIS/A070080|A070080]]''', Triangles with integer sides, areas and in-radii
** Additional '''[[OEIS/FASS_curves|FASS curves]]''': space-'''f'''illing, self-'''a'''voiding, '''s'''imple and self-'''s'''imilar curves
* '''[https://oeis.org/A070165 A070165]''', Collatz conjecture: '''[[OEIS/3x%2B1_Problem]]''' (solution proposal)
* '''[[OEIS/A291939|A291939]]''': 1, 12, 19, 27, 37 - overlapping of Collatz sequences, was <code>unkn</code>, with visualization
* '''[http://oeis.org/A112273 A112273]''': 5, 15, 365, 945 - a puzzle sequence
* '''[http://oeis.org/A112273 A112273]''': 5, 15,365, 945 - a puzzle sequence
** my guess: 5*3^0, 5*3^1, 5*73 (or should that be 315 = 5*7*3^2 ?), 5*7*3^3
* '''[[OEIS/Engel_expansion|Engel expansion]]''' - English translation of Friedrich Engel's speech: ''Entwicklung der Zahlen nach Stammbrüchen.'' Verhandlungen der 52. Verammlung Deutscher Philologen und Schulmänner, 1913, Marburg, pp. 190-191
* '''[https://oeis.org/A213457 A213457]''' Intertwining numbers: a(8) = 1058349286
* '''[[OEIS/A291939|A291939]]''': 1, 12, 19, 27, 37 - overlapping of Collatz sequences, was <code>unkn</code>, with 3D visualization
 
===Index sections===
* [https://oeis.org/wiki/Index_to_OEIS:_Section_Rec Index of linear recurrences with constant coefficients], mechanically generated every 3rd month
* [https://oeis.org/w/index.php?title=Index_to_OEIS:_Sums_of_like_powers Index to OEIS: Sums of like powers] 2020-08-04
* [[OEIS/Wikipedia index]]

Latest revision as of 08:47, 6 April 2024

The On-Line Encyclopedia of Integer Sequences® of Neil Sloane et al.

  • A Handbook of Integer Sequences, N. J. A. Sloane, Academic Press, New York and London, 1973.
  • The_Encyclopedia_of_Integer_Sequences, N. J. A. Sloane and S. Plouffe, Academic Press, San Diego, 1995, 587 pp. ISBN 0-12-558630-2.

Groups of sequences implemented for jOEIS

  • morfix, fixed points of morphisms
  • squaredig, numbers which have a subset of digits in the number and its square

Small projects

Cf. my OEIS wiki user page

Individual sequences

  • A003828, Numbers n such that n^4 is a primitive sum of 3 positive fourth powers: 422481, 2813001, 8707481, 12197457, 16003017, 16430513, 20615673, 44310257, 68711097, 117112081, 145087793, 156646737, 589845921, 638523249, 873822121, 1259768473, 1679142729, 1787882337, 1871713857
  • A035505, Kimberling's expulsion (shuffle) array array visualization
  • A070080, Triangles with integer sides, areas and in-radii
  • A070165, Collatz conjecture: OEIS/3x+1_Problem (solution proposal)
  • A112273: 5, 15, 365, 945 - a puzzle sequence
    • my guess: 5*3^0, 5*3^1, 5*73 (or should that be 315 = 5*7*3^2 ?), 5*7*3^3
  • A213457 Intertwining numbers: a(8) = 1058349286
  • A291939: 1, 12, 19, 27, 37 - overlapping of Collatz sequences, was unkn, with 3D visualization

Index sections

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