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

0,2

Links

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

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

Crossrefs

Cf. A258829, A258830.

Sequence in context: A203534 A166989 A143550 * A259658 A350952 A000175

Adjacent sequences: A259210 A259211 A259212 * A259214 A259215 A259216

Keyword

nonn

Author

Vaclav Kotesovec, Jun 21 2015

Status

approved