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.

A056200 a(n) = 2^n - A056045(n).

Original entry on oeis.org

1, 1, 4, 5, 26, 22, 120, 149, 418, 716, 2036, 2378, 8178, 12846, 29294, 50709, 131054, 193972, 524268, 843260, 1979520, 3488618, 8388584, 13190042, 33501276, 56707912, 129527950, 227113934, 536870882, 887838482, 2147483616, 3683332117, 8396392382, 14846262368, 34352689180
Offset: 1

Views

Author

Labos Elemer, Aug 02 2000

Keywords

Crossrefs

Programs

  • Mathematica
    a[n_] := 2^n - DivisorSum[n, Binomial[n, #] &]; Array[a, 40] (* Amiram Eldar, Aug 18 2024 *)
  • PARI
    a(n) = 2^n - sumdiv(n, d, binomial(n, d)); \\ Michel Marcus, Aug 25 2019

Formula

a(p) = 2^p - p - 1 for a prime p.

Extensions

More terms from Amiram Eldar, Aug 18 2024