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.

A279726 Partial sums of A187619.

Original entry on oeis.org

0, 0, 0, 2, 6, 8, 16, 32, 44, 64, 92, 118, 150, 174, 202, 234, 298, 358, 382, 440, 512, 598, 686, 808, 924, 1002, 1130, 1228, 1336, 1480, 1560, 1762, 1966, 2026, 2210, 2426, 2614, 2840, 3132, 3300, 3496, 3812, 4072, 4240, 4616, 4852, 5068, 5402, 5522, 5826, 6234, 6512
Offset: 1

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Author

Wesley Ivan Hurt, Dec 17 2016

Keywords

Crossrefs

Programs

  • Maple
    with(numtheory): a:=n->2*add(add( (pi(i)-pi(i-1)) * (pi(2*k-i)-pi(2*k-i-1)) * (k-i), i=3..k), k=1..n): seq(a(n), n=1..100);
  • Mathematica
    Accumulate@ Table[2 Sum[Boole[PrimeQ@ i] Boole[PrimeQ[2 n - i]] (n - i), {i, 3, n}], {n, 56}] (* Michael De Vlieger, Dec 17 2016 *)

Formula

a(n) = 2 * Sum_{k=1..n} (Sum_{i=3..k} A010051(i) * A010051(2k-i) * (k-i)).