OFFSET
0,3
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..400
FORMULA
a(n) = A081125(n)^2.
a(n) = Sum_{k=0..n} (-1)^(n-k)*binomial(n,k)*A195009(n,k).
a(n) = n!^2*[x^n] (1+x)*BesselI(0,2*x). Here [x^n]f(x) denotes the coefficient of x^n in f(x).
Conjecture: a(n) + 8*a(n-1) - 4*(n-2)*(n+2)*a(n-2) + 16*(-2*n^2 + 6*n - 3)*a(n-3) - 64*(n-3)^2*a(n-4) = 0. - R. J. Mathar, Oct 03 2014
MAPLE
A193282 := n -> (n!/iquo(n, 2)!)^2;
MATHEMATICA
Table[(n!/(Floor[n/2]!))^2, {n, 0, 20}] (* Harvey P. Dale, Jul 30 2020 *)
PROG
(Magma) [(Factorial(n)/Factorial(Floor(n/2)))^2: n in [0..20]]; // Vincenzo Librandi, Sep 11 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, Sep 08 2011
STATUS
approved