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.

A293688 Partial sums of A002251.

Original entry on oeis.org

0, 2, 3, 8, 15, 18, 28, 32, 45, 60, 66, 84, 104, 112, 135, 144, 170, 198, 209, 240, 252, 286, 322, 336, 375, 416, 432, 476, 493, 540, 589, 608, 660, 714, 735, 792, 814, 874, 936, 960, 1025, 1050, 1118, 1188, 1215, 1288, 1363, 1392, 1470, 1500, 1581, 1664, 1696, 1782, 1815
Offset: 0

Views

Author

Enrique Navarrete, Oct 14 2017

Keywords

Crossrefs

Programs

  • Mathematica
    With[{n = 34}, Accumulate@ Prepend[Take[Values@ #, LengthWhile[#, # == 1 &] &@ Differences@ Keys@ #], 0] &@ Sort@ Flatten@ Map[{#1 -> #2, #2 -> #1} & @@ # &, Transpose@ {Array[Floor[# GoldenRatio] &, n], Array[Floor[# GoldenRatio^2] &, n]}]] (* Michael De Vlieger, Nov 14 2017 *)

Formula

a(n) = (n+1)*A005206(n) where A005206 is the Hofstadter G-sequence. [Apparently this is a conjecture, rather than a theorem. - N. J. A. Sloane, Mar 03 2019]
a(n) = Sum_{k=0..n} A002251(k). - Michel Marcus, Nov 13 2017

Extensions

Offset changed to 0 by Michel Marcus, Nov 13 2017