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.

A023514 a(n) = sum of exponents in prime-power factorization of prime(n) + 1.

Original entry on oeis.org

1, 2, 2, 3, 3, 2, 3, 3, 4, 3, 5, 2, 3, 3, 5, 4, 4, 2, 3, 5, 2, 5, 4, 4, 3, 3, 4, 5, 3, 3, 7, 4, 3, 4, 4, 4, 2, 3, 5, 3, 5, 3, 7, 2, 4, 5, 3, 6, 4, 3, 4, 6, 3, 5, 3, 5, 5, 5, 2, 3, 3, 4, 4, 5, 2, 3, 3, 3, 4, 4, 3, 6, 5, 3, 4, 8, 4, 2, 3, 3, 5, 2, 7, 3, 5, 4, 5, 2, 4, 5, 5, 7, 4, 4, 5, 6, 4, 4, 3
Offset: 1

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Crossrefs

Programs

  • Maple
    with(numtheory):
    a:= n-> add(i[2], i=ifactors(ithprime(n)+1)[2]):
    seq(a(n), n=1..100);
  • Mathematica
    Array[Plus@@Last/@FactorInteger[Prime[ # ]+1]&,6! ] (* Vladimir Joseph Stephan Orlovsky, Feb 28 2010 *)
  • PARI
    a(n) = bigomega(prime(n)+1); \\ Michel Marcus, Jan 04 2016

Formula

a(n) = A001222(A000040(n)+1). - Zak Seidov, Jan 04 2016