OEIS: Difference between revisions

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* '''[[OEIS/B-file_check|B-file check]]''', initiated by Martin Pedersen
* '''[[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  
* '''[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])
* '''[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/Generating_Functions_and_Recurrences|Generating Functions and Recurrences]]'''
* '''[[OEIS/Generating_Functions_and_Recurrences|Generating Functions and Recurrences]]'''

Revision as of 15:37, 4 August 2020

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
  • 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