A128275 Absolute values of numerators of series expansion of sinh(x)/sqrt((cosh(x))^2+(sinh(x))^2) about 0 (odd indexed coefficients only).

1, 5, 121, 1369, 698161, 22394737, 25947503401, 29819441791, 3389281372287841, 354891998735343073, 1147649139272698443481, 179707467079684030326841, 76137452589606191547280211, 183280927961986287722231696209, 1163176750283121903011836076436361

Offset: 0

Author

Artur Jasinski, Feb 22 2007

Keywords

• nonn

Crossrefs

Cf. A012085, A012193, A128274.

Programs

Mathematica

Series[Sinh[x]/(Sqrt[Cosh[x]^2 + Sinh[x]^2]), {x, 0, 20}]

Extensions

Offset 0 and more terms from Alois P. Heinz, Apr 08 2021