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A349114
a(n) = 4^n * P(n, 2*n), where P(n, x) is n-th Legendre polynomial.
2
1, 8, 376, 33984, 4526176, 797459200, 174910868224, 45926958135296, 14047764722238976, 4905641267399503872, 1925859774286175997952, 839619968812285810868224, 402496047174560754869846016, 210424519428145503482634174464, 119148510992477432889126160826368
OFFSET
0,2
LINKS
Eric Weisstein's World of Mathematics, Legendre Polynomial.
FORMULA
a(n) ~ 2^(4*n) * n^(n - 1/2) / sqrt(Pi).
MATHEMATICA
Table[4^n*LegendreP[n, 2*n], {n, 0, 16}]
PROG
(PARI) a(n) = 4^n*pollegendre(n, 2*n); \\ Michel Marcus, Nov 08 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Nov 08 2021
STATUS
approved