A012848 tanh(sec(x)*arctanh(x))=x+3/3!*x^3-15/5!*x^5-1869/7!*x^7-88959/9!*x^9...

1, 3, -15, -1869, -88959, 202499, 974640433, 190241481587, 15481756625281, -5564353308576125, -3510791865515349775, -961065703006847944525, 92025876595389114977025, 299254465799630697304777347

Offset

0,2

Links

Table of n, a(n) for n=0..13.

Crossrefs

Sequence in context: A231656 A096368 A016066 * A322714 A202621 A076046

Adjacent sequences: A012845 A012846 A012847 * A012849 A012850 A012851

Keyword

sign

Author

Patrick Demichel (patrick.demichel(AT)hp.com)

Status

approved