A372988 a(n) = (2n)!/(n!*a(n-2)), with a(0) = 1, a(1) = 1.

1, 1, 12, 120, 140, 252, 4752, 68640, 109200, 257040, 6139584, 109549440, 210974400, 591192000, 16576876800, 343108846080, 758663942400, 2419157664000, 76585170816000, 1777303822694400, 4379008275532800, 15472932418944000, 540078624594432000, 13756331587654656000

Offset

0,3

Links

Table of n, a(n) for n=0..23.

Mathematica

a[0] = 1; a[1] = 1;
a[n_] := a[n] = (2n)!/(n!*a[n - 2]);
Table[a[n], {n, 0, 20}]

Crossrefs

Cf. A372986, A372987.

Sequence in context: A075366 A276668 A076633 * A110423 A006953 A164877

Adjacent sequences: A372985 A372986 A372987 * A372989 A372990 A372991

Keyword

nonn

Author

Clark Kimberling, Jul 09 2024

Status

approved