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.

A294114 Sum of the larger parts of the partitions of 2n into two parts with smaller part prime.

Original entry on oeis.org

0, 2, 7, 11, 20, 26, 39, 47, 55, 63, 82, 92, 115, 127, 139, 151, 180, 194, 227, 243, 259, 275, 314, 332, 350, 368, 386, 404, 451, 471, 522, 544, 566, 588, 610, 632, 691, 715, 739, 763, 828, 854, 923, 951, 979, 1007, 1082, 1112, 1142, 1172, 1202, 1232, 1315
Offset: 1

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Author

Wesley Ivan Hurt, Oct 22 2017

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Sum[(2 n - i) (PrimePi[i] - PrimePi[i - 1]), {i, n}], {n, 80}]
    Table[Total[Select[IntegerPartitions[2 n,{2}],PrimeQ[#[[2]]]&][[All,1]]],{n,60}] (* Harvey P. Dale, Apr 19 2020 *)

Formula

a(n) = Sum_{i=1..n} (2*n - i) * c(i), where c is the prime characteristic (A010051).