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.

A231502 a(n) = Sum_{i=0..n} wt(i)^4, where wt() = A000120().

Original entry on oeis.org

0, 1, 2, 18, 19, 35, 51, 132, 133, 149, 165, 246, 262, 343, 424, 680, 681, 697, 713, 794, 810, 891, 972, 1228, 1244, 1325, 1406, 1662, 1743, 1999, 2255, 2880, 2881, 2897, 2913, 2994, 3010, 3091, 3172, 3428, 3444, 3525, 3606, 3862, 3943, 4199, 4455, 5080, 5096, 5177, 5258, 5514, 5595, 5851, 6107, 6732, 6813, 7069
Offset: 0

Views

Author

N. J. A. Sloane, Nov 12 2013

Keywords

Crossrefs

Programs

  • Mathematica
    Accumulate @ (Table[DigitCount[n, 2, 1], {n, 0, 60}]^4) (* Amiram Eldar, Jan 20 2022 *)
  • PARI
    a(n) = sum(i=0, n, hammingweight(i)^4); \\ Michel Marcus, Nov 12 2013

Formula

a(n) ~ n * (log(n)/(2*log(2)))^4 + O(n*log(n)^3) (Stolarsky, 1977). - Amiram Eldar, Jan 20 2022
a(n) = Sum_{k=0..floor(log_2(n+1))} k^4 * A360189(n,k). - Alois P. Heinz, Mar 06 2023