A012658 sech(tanh(x)*log(x+1))=1-12/4!*x^4+60/5!*x^5-90/6!*x^6+420/7!*x^7...

1, 0, 0, 0, -12, 60, -90, 420, -2240, -56448, 607320, -1834800, 23242824, -229079136, -4388159776, 77755073760, -443094745600, 10064071501184, -151026375297216, -1331806005060480, 38225434479768448

Offset

0,5

Links

Table of n, a(n) for n=0..20.

Crossrefs

Sequence in context: A381636 A359419 A372135 * A012407 A009093 A012400

Adjacent sequences: A012655 A012656 A012657 * A012659 A012660 A012661

Keyword

sign

Author

Patrick Demichel

Status

approved