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.

A122247 Partial sums of A005187.

Original entry on oeis.org

0, 1, 4, 8, 15, 23, 33, 44, 59, 75, 93, 112, 134, 157, 182, 208, 239, 271, 305, 340, 378, 417, 458, 500, 546, 593, 642, 692, 745, 799, 855, 912, 975, 1039, 1105, 1172, 1242, 1313, 1386, 1460, 1538, 1617, 1698, 1780, 1865, 1951, 2039, 2128, 2222, 2317, 2414
Offset: 0

Views

Author

Paul Barry, Aug 27 2006

Keywords

Crossrefs

Cf. A005187 (first differences).

Programs

  • Maple
    b:= proc(n) option remember; `if`(n=0, 0, b(iquo(n, 2))+n) end:
    a:= proc(n) option remember; `if`(n=0, 0, b(n)+a(n-1)) end:
    seq(a(n), n=0..50);  # Alois P. Heinz, Jan 25 2022
  • Mathematica
    Accumulate[Table[2n-Count[IntegerDigits[2 n,2],1],{n,0,70}]] (* Harvey P. Dale, Oct 22 2011 *)

Formula

a(n) = Sum_{k=1..n} Sum_{j=0..n} floor(k/2^j).
G.f.: (1/(1-x))*Sum_{k>=0} x^(2^k)/((1-x)*(1-x^(2^k))).