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A295773
a(n) = Sum_{k=0..n} binomial(k^2, k).
3
1, 2, 8, 92, 1912, 55042, 2002834, 87903418, 4514068786, 265401903136, 17575711359576, 1294325676386112, 104913619501093500, 9281271920245432932, 889811788303594625412, 91895379599481072720852, 10170646981621794947354052, 1200909691326112843842751962
OFFSET
0,2
LINKS
FORMULA
a(n) ~ exp(n - 1/2) * n^(n - 1/2) / sqrt(2*Pi).
MATHEMATICA
Table[Sum[Binomial[k^2, k], {k, 0, n}], {n, 0, 20}]
PROG
(PARI) a(n) = sum(k=0, n, binomial(k^2, k)); \\ Michel Marcus, Jan 10 2019
(Magma) [&+[Binomial(k^2, k): k in [0..n]]: n in [0..20]]; // Vincenzo Librandi, Jan 10 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Nov 27 2017
STATUS
approved