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.

A238496 Number of prime factors in A052129(n).

Original entry on oeis.org

0, 0, 1, 3, 8, 17, 36, 73, 149, 300, 602, 1205, 2413, 4827, 9656, 19314, 38632, 77265, 154533, 309067, 618137, 1236276, 2472554, 4945109, 9890222, 19780446, 39560894, 79121791, 158243585, 316487171, 632974345, 1265948691, 2531897387
Offset: 0

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Author

Bob Selcoe, Feb 27 2014

Keywords

Crossrefs

Programs

  • Maple
    with(numtheory): seq(add(2^(n-i)*bigomega(i), i=1..n), n=0..40); # Ridouane Oudra, Nov 11 2019
  • PARI
    a(n) = if (n==0, 0, 2*a(n-1) + bigomega(n)); \\ Michel Marcus, May 25 2014

Formula

a(n) = 2*a(n-1) + A001222(n) for n>=1; a(0) = 0.
a(n) = Sum_{i=1..n} 2^(n-i)*A001222(i). - Ridouane Oudra, Nov 11 2019