A064072 Generalized tangent number d(7,n).

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

Offset: 1

Author

Eric W. Weisstein, Aug 31 2001

Keywords

• nonn
• easy

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.

Crossrefs

Cf. A064068, A349266, A349264.

Programs

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

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

Extensions

Offset changed to 1 by Lars Blomberg, Sep 07 2015