cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A005705 Number of partitions of 4*n into powers of 4.

Original entry on oeis.org

1, 2, 3, 4, 6, 8, 10, 12, 15, 18, 21, 24, 28, 32, 36, 40, 46, 52, 58, 64, 72, 80, 88, 96, 106, 116, 126, 136, 148, 160, 172, 184, 199, 214, 229, 244, 262, 280, 298, 316, 337, 358, 379, 400, 424, 448, 472, 496, 524, 552, 580, 608, 640, 672, 704, 736, 772, 808, 844
Offset: 0

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Comments

Also number of partitions of 4*n+k into powers of 4 where k=1,2,3. - Michael Somos, Mar 15 2020

References

  • R. K. Guy, personal communication.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Column k=4 of A292477.

Programs

  • Mathematica
    Fold[Append[#1, Total[Take[Flatten[Transpose[Table[#1, {4}]]], #2]]] &, {1},  Range[2, 20]] (* Birkas Gyorgy, Apr 18 2011 *)

Formula

a(n) = a(n-1) + a(floor(n/4)).
G.f.: T(x)=(1-x)^(-1)/(Product_{k>=0} 1-x^(4^k)), it satisfies T(x)=(1-x^4)/(1-x)^2*T(x^4). - Joerg Arndt, May 12 2010

Extensions

Formula and more terms from Henry Bottomley, Apr 30 2001