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A329964
a(n) = (n!/floor(1+n/2)!)^2.
2
1, 1, 1, 9, 16, 400, 900, 44100, 112896, 9144576, 25401600, 3073593600, 9032601600, 1526509670400, 4674935865600, 1051860569760000, 3324398837760000, 960751264112640000, 3112834095724953600, 1123733108556708249600, 3714820193575895040000
OFFSET
0,4
FORMULA
a(n) = A262033(n)^2.
Sum_{n>=0} 1/a(n) = 29/16 + (3/16)*Pi*StruveL(-1, 1/2) + (57/64)*Pi*StruveL(0, 1/2) + (1/4)*Pi*StruveL(1, 1/2), where StruveL is the modified Struve function. - Amiram Eldar, Dec 04 2022
MAPLE
A329964 := n -> (n!/floor(1+n/2)!)^2:
seq(A329964(n), n=0..20);
MATHEMATICA
a[n_] := (n!/Floor[1 + n/2]!)^2; Array[a, 20, 0] (* Amiram Eldar, Dec 04 2022 *)
CROSSREFS
Cf. A262033.
Sequence in context: A053911 A171522 A236287 * A050802 A264519 A136313
KEYWORD
nonn
AUTHOR
Peter Luschny, Dec 04 2019
STATUS
approved