A259213 Column 2 of triangle A258829.

1, 2, 11, 38, 263, 1260, 10871, 66576, 694599, 5182960, 63738259, 561098224, 7969169739, 80865956192, 1304923903919, 14998292190464, 271341955926479, 3484403002454016, 69899466563099435, 991886288235459072, 21861082423955691795, 339715268249655012352

Offset: 0

Author

Vaclav Kotesovec, Jun 21 2015

Keywords

• nonn

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 0..460

Crossrefs

Cf. A258829, A258830.

Formula

a(n) ~ n! * (d*(1-(-1)^n) + 1+(-1)^n)*c/2 * d^n * n^2, where d = 0.8218983778054251105765881248... = 1/(r*sqrt(2)), where r is the root of the equation cot(r)=r and c = 0.986093542875063325007949... . - Vaclav Kotesovec, Jun 21 2015, updated Mar 16 2024