A013325 Numerator of [x^n] in the Taylor series arccosh(exp(x)-arctanh(x))= x-x^2/6-x^3/72 -359*x^4/2160 -1681*x^5/51840 -52981*x^6/435456 -...

1, -1, -1, -359, -1681, -52981, -1887113, -27492467, -3259141, -1194145112779, -55919619312049, -7462251938940527, -113201511292945547, -1055956853774285077, -44032898634010565651, -75833822693358307239889

Offset

1,4

Comments

The inner function exp(x)-arctanh(x) = 1+x^2/2! -x^3/3! +x^4/4! -23*x^5/120 + x^6/6! -719*x^7/7!.. has e.g.f. coefficients apparently closely related to A127230.

Links

Table of n, a(n) for n=1..16.

Crossrefs

Sequence in context: A175537 A142852 A158307 * A344284 A179678 A101996

Adjacent sequences: A013322 A013323 A013324 * A013326 A013327 A013328

Keyword

sign,frac

Author

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

Extensions

Values replaced by numerators. - R. J. Mathar, Dec 22 2011

Status

approved