A025212 a(n) = floor(2nd elementary symmetric function of Sum_{j=1..k} 1/j, k = 1,2,...,n).

1, 6, 15, 29, 51, 79, 117, 163, 220, 287, 365, 455, 558, 673, 802, 945, 1102, 1273, 1460, 1663, 1881, 2116, 2368, 2636, 2922, 3226, 3548, 3888, 4247, 4625, 5023, 5439, 5876, 6333, 6810, 7307, 7826, 8366, 8927, 9510, 10114, 10741, 11390, 12061, 12755, 13472, 14213

Offset

2,2

Links

Robert Israel, Table of n, a(n) for n = 2..1000

Maple

es2:=  proc(L) convert(map(convert, combinat:-choose(L, 2), `*`), `+`) end proc:
f:= proc(n) local k; floor(es2(ListTools:-PartialSums([seq(1/k, k=1..n)]))) end proc:
map(f, [$2..50]); # Robert Israel, Dec 13 2022

Crossrefs

Sequence in context: A005286 A298877 A229063 * A024972 A048749 A355527

Adjacent sequences: A025209 A025210 A025211 * A025213 A025214 A025215

Keyword

nonn

Author

Clark Kimberling

Status

approved