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.

A309431 a(n) = Sum_{k=2..p} (-1)^k * A240236(p, k), where p is n-th prime.

Original entry on oeis.org

1, 1, 0, 2, 5, -2, -6, 1, 10, 7, 13, -11, -15, -5, 32, 0, 34, -23, 5, 30, -66, 33, 29, -18, -60, -17, 13, 69, -21, -65, 65, 17, 8, 50, -6, 24, -33, -23, 130, 13, 115, -93, 184, -132, 4, 48, -11, 31, 70, -99, -23, 192, -258, 154, -68, 155, -18, 16, -35, -101, -11
Offset: 1

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Author

Seiichi Manyama, Aug 06 2019

Keywords

Crossrefs

Programs

  • PARI
    {a(n) = sum(k=2, prime(n), (-1)^k*sumdigits(prime(n), k))}

Formula

a(n) = A309531(A000040(n)).