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.

A326461 Sum of the third largest parts in the partitions of n into 8 primes.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 5, 5, 8, 10, 12, 14, 19, 21, 27, 34, 35, 44, 57, 64, 67, 88, 87, 115, 121, 142, 146, 191, 176, 233, 232, 289, 271, 369, 336, 455, 414, 537, 500, 687, 588, 816, 722, 974, 843, 1179, 977, 1392, 1172
Offset: 0

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Author

Wesley Ivan Hurt, Jul 06 2019

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Total[Select[IntegerPartitions[n,{8}],AllTrue[#,PrimeQ]&][[;;,3]]],{n,0,70}] (* Harvey P. Dale, Apr 13 2025 *)

Formula

a(n) = Sum_{p=1..floor(n/8)} Sum_{o=p..floor((n-p)/7)} Sum_{m=o..floor((n-o-p)/6)} Sum_{l=m..floor((n-m-o-p)/5)} Sum_{k=l..floor((n-l-m-o-p)/4)} Sum_{j=k..floor((n-k-l-m-o-p)/3)} Sum_{i=j..floor((n-j-k-l-m-o-p)/2)} c(p) * c(o) * c(m) * c(l) * c(k) * c(j) * c(i) * c(n-i-j-k-l-m-o-p) * j, where c = A010051.
a(n) = A326455(n) - A326456(n) - A326457(n) - A326458(n) - A326459(n) - A326460(n) - A326462(n) - A326463(n).