A276960 a(n) = A000262(n)^2.
1, 1, 9, 169, 5329, 251001, 16410601, 1416242689, 155514288609, 21128299481809, 3474052208270281, 679096541717605881, 155504946117339546289, 41199419449380747871369, 12496348897836314700506409
Offset: 0
Keywords
Programs
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Mathematica
Table[HypergeometricPFQ[{-n+1,-n},{},1]^2,{n,0,100}]
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Maxima
makelist(hypergeometric([-n+1,-n],[],1)^2,n,0,12);
Formula
Recurrence: (2*n+3)*a(n+3)-(2*n+5)*(3*n^2+13*n+13)*a(n+2)+(n+2)*(n+1)*(2*n+3)*(3*n^2+13*n+13)*a(n+1)-n^2*(n+1)^3*(n+2)*(2 n+5)*a(n) = 0.
Asymptotic: a(n) ~ exp(-2*n+4*sqrt(n)-1)*n^(2*n-1/2)/2 * (1 - 5/(24*sqrt(n)) - 35/(1152*n)).