A127230 a(n) = (2n)! - 1.

1, 23, 719, 40319, 3628799, 479001599, 87178291199, 20922789887999, 6402373705727999, 2432902008176639999, 1124000727777607679999, 620448401733239439359999, 403291461126605635583999999, 304888344611713860501503999999, 265252859812191058636308479999999

Offset: 1

Author

Artur Jasinski, Jan 09 2007

Keywords

• nonn

Crossrefs

Cf. A010050, A028387, A062938, A127227, A127228, A127229, A127231.

Programs

Mathematica

Table[(2n)! - 1, {n, 1, 30}]

Formula

a(n) = -1 + A010050(n).

Extensions

Entry revised by Alois P. Heinz, Mar 27 2021