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A359658
a(n) = Sum_{k=0..n} k^(k * (n-k) + 1).
1
0, 1, 3, 12, 118, 3345, 337337, 117813304, 182877273548, 1095343802746641, 33833602932485958015, 4588786457956655542361532, 3347980595386754115503487966082, 13023291362471615806961306534915589217
OFFSET
0,3
FORMULA
G.f.: Sum_{k>=0} k * x^k/(1 - k^k * x).
PROG
(PARI) a(n) = sum(k=0, n, k^(k*(n-k)+1));
(PARI) my(N=20, x='x+O('x^N)); concat(0, Vec(sum(k=0, N, k*x^k/(1-k^k*x))))
CROSSREFS
Sequence in context: A009254 A377066 A133987 * A194506 A280458 A294198
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jan 10 2023
STATUS
approved