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A349116
a(n) = Sum_{m=1..n} (Sum_{k=1..m} (Sum_{j=1..k} j^n)).
3
1, 7, 57, 605, 7990, 126378, 2331462, 49183590, 1168343775, 30871159429, 898302280271, 28547663567787, 983905660878140, 36556999252315556, 1456715662183096092, 61973464872507939132, 2803744852868605501965, 134413716665674685292183, 6807005707226954237422477
OFFSET
1,2
LINKS
FORMULA
a(n) ~ c * n^n, where c = 1/(1 - 3/exp(1) + 3/exp(2) - 1/exp(3)) = 3.959134481...
MATHEMATICA
Table[Sum[Sum[Sum[j^n, {j, 1, k}], {k, 1, m}], {m, 1, n}], {n, 1, 20}]
CROSSREFS
Sequence in context: A122649 A051846 A231540 * A337556 A337022 A316442
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Nov 08 2021
STATUS
approved