OEIS: Difference between revisions
Jump to navigation
Jump to search
imported>Gfis A035505 was mistyped |
imported>Gfis →Small Projects: bfcheck |
||
| Line 4: | Line 4: | ||
===Small Projects=== | ===Small Projects=== | ||
Cf. my [https://oeis.org/wiki/User:Georg_Fischer OEIS wiki user page] | Cf. my [https://oeis.org/wiki/User:Georg_Fischer OEIS wiki user page] | ||
* '''[ | * '''[OEIS/B-file_check|B-file check]]''', initiated by Martin Pedersen | ||
* '''[[OEIS/Broken_Links|Broken links]]''' detection and repair | * '''[[OEIS/Broken_Links|Broken links]]''' detection and repair | ||
* '''[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]) | * '''[https://oeis.org/wiki/User:Georg_Fischer/Coincidences Coincidences]''' - search lists for sequences with common terms* '''[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. Versammlung Deutscher Philologen und Schulmänner, 1913, Marburg, pp. 190-191 | * '''[[OEIS/Engel_expansion|Engel expansion]]''' - English translation of Friedrich Engel's speech: ''Entwicklung der Zahlen nach Stammbrüchen.'' Verhandlungen der 52. Versammlung Deutscher Philologen und Schulmänner, 1913, Marburg, pp. 190-191 | ||
* '''[[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 | * '''[[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 | ||
| Line 12: | Line 12: | ||
* '''[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] | * '''[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 | * '''[[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 | ||
===Individual sequences=== | ===Individual sequences=== | ||
* '''[[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 | ||
Revision as of 18:28, 24 January 2019
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.
Small Projects
Cf. my OEIS wiki user page
- [OEIS/B-file_check|B-file check]], initiated by Martin Pedersen
- Broken links detection and repair
- Coincidences - search lists for sequences with common terms* WTM World of Terrel Trotter's Math (archive copy of the original webpage of 2004, c.f. his OEIS user page)
- Engel expansion - English translation of Friedrich Engel's speech: Entwicklung der Zahlen nach Stammbrüchen. Verhandlungen der 52. Versammlung Deutscher Philologen und Schulmänner, 1913, Marburg, pp. 190-191
- A220952: 0, 1, 2, 3, 4, 9, 14, 19, 18, 17, 16, 11, 12, 13, ..., 49 ... by Donald E. Knuth, Feb. 20, 2013, was
unkn, with additional FASS curves: space-filling, self-avoiding, simple and self-similar curves - A131388, and A131393 with recovered Rule 2 and generalized negative-positive incrementing sequences of Clark Kimberling, with listing and program
- A030707, A055187, A217760 and related sequences, listing and program for generalized cumulative counting, Clark Kimberling's problem no. 4
- Triangles with interlacing rows, Clark Kimberling's problem no. 18; Perl and C programs find 1, 2, 20, 1744, 2 002 568, 42 263 042 752 triangles for the between condition
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
- 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