A064072 Generalized tangent number d(7,n).

8, 904, 355688, 296327464, 423645846728, 925434038426824, 2866986638191472168, 11956421282992330042984, 64584221654333725499376008, 438640634423372575622395751944, 3658596185733807024739320857622248, 36763878323837308563984663576886049704

Offset

1,1

Links

Lars Blomberg, Table of n, a(n) for n = 1..180

D. Shanks, Generalized Euler and class numbers, Math. Comp. 21 1967 663-688.

D. Shanks, Corrigenda to: "Generalized Euler and class numbers", Math. Comp. 22 (1968), 699.

Eric Weisstein's World of Mathematics, Tangent Number.

Formula

a(n) = (2*n-1)!*[x^(2*n-1)](sec(7*x)*(-sin(2*x) + sin(4*x) + sin(6*x))). - Peter Luschny, Nov 21 2021

Maple

egf := sec(7*x)*(-sin(2*x) + sin(4*x) + sin(6*x)): ser := series(egf, x, 24):
seq((2*n-1)!*coeff(ser, x, 2*n-1), n = 1..10); # Peter Luschny, Nov 21 2021

Crossrefs

Cf. A064068, A349266, A349264.

Sequence in context: A290023 A112578 A112579 * A146536 A189646 A348795

Adjacent sequences: A064069 A064070 A064071 * A064073 A064074 A064075

Keyword

nonn,easy

Author

Eric W. Weisstein, Aug 31 2001

Extensions

Offset changed to 1 by Lars Blomberg, Sep 07 2015

Status

approved