login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A258358
Sum over all partitions lambda of n into 3 distinct parts of Product_{i:lambda} prime(i).
2
30, 42, 136, 293, 551, 892, 1765, 2570, 4273, 6747, 9770, 13958, 21206, 28280, 39702, 54913, 72227, 94682, 127095, 160046, 206119, 263581, 327790, 406354, 512372, 616764, 754412, 921169, 1100165, 1314196, 1584835, 1854384, 2191013, 2590565, 3006512, 3495086
OFFSET
6,1
LINKS
MAPLE
g:= proc(n, i) option remember; convert(series(`if`(n=0, 1,
`if`(i<1, 0, add(g(n-i*j, i-1)*(ithprime(i)*x)^j
, j=0..min(1, n/i)))), x, 4), polynom)
end:
a:= n-> coeff(g(n$2), x, 3):
seq(a(n), n=6..60);
MATHEMATICA
g[n_, i_] := g[n, i] = If[n == 0, 1, If[i < 1, 0, Sum[g[n - i j, i - 1] (Prime[i] x)^j, {j, 0, Min[1, n/i]}]]];
a[n_] := Coefficient[g[n, n], x, 3];
a /@ Range[6, 60] (* Jean-François Alcover, Dec 11 2020, after Alois P. Heinz *)
CROSSREFS
Column k=3 of A258323.
Cf. A000040.
Sequence in context: A257832 A050776 A268697 * A090692 A196677 A225326
KEYWORD
nonn
AUTHOR
Alois P. Heinz, May 27 2015
STATUS
approved