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.

A187619 Sum of the differences of the parts in each Goldbach partition of 2n, A187129(n) - A185297(n).

Original entry on oeis.org

0, 0, 2, 4, 2, 8, 16, 12, 20, 28, 26, 32, 24, 28, 32, 64, 60, 24, 58, 72, 86, 88, 122, 116, 78, 128, 98, 108, 144, 80, 202, 204, 60, 184, 216, 188, 226, 292, 168, 196, 316, 260, 168, 376, 236, 216, 334, 120, 304, 408, 278, 340, 472, 392, 454, 604, 452, 372, 724, 216, 330, 580, 162, 472, 542, 392, 366, 540, 470, 592, 838, 384, 390, 828
Offset: 2

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Author

N. J. A. Sloane, Mar 12 2011

Keywords

Crossrefs

Cf. A226237 (Sum of sums), A045917.

Programs

  • Maple
    with(numtheory):
    A279725:=n->2*add( (pi(i)-pi(i-1)) * (pi(2*n-i)-pi(2*n-i-1)) * (n-i), i=3..n):
    seq(A279725(n), n=1..100); # Wesley Ivan Hurt, Dec 17 2016
  • Mathematica
    Table[2 Sum[(n - i) Floor[2/PrimeOmega[2 n*i - i^2]], {i, 2, n}], {n, 2, 100}] (* Wesley Ivan Hurt, Dec 20 2013 *)

Formula

a(n) = 2 * Sum_{i=2..n} (n-i) * A064911(2*n*i-i^2). - Wesley Ivan Hurt, Dec 20 2013
a(n) = 2 * Sum_{i=3..n} c(i) * c(2*n-i) * (n-i), where c = A010051. - Wesley Ivan Hurt, Dec 17 2016

Extensions

More descriptive name by Wesley Ivan Hurt, Dec 20 2013