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A013558 E.g.f. -log(sech(x) - log(x+1)). 1
0, 1, 1, 4, 3, 33, 155, 1195, 5418, 72373, 496027, 6851051, 59706592, 986009607, 10430165629, 193892831665, 2439695949632, 50409517110169, 737532991565959, 16755308524034767, 279581740874221016 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

The inner function is sech(x) - log(1+x) = 1 - x - x^3/3 + 11*x^4/24 - x^5/5 + 59*x^6/720 - x^7/7 + ... = 1 - x/1! + 0*x^2/2! - 2*x^3/3! + 11*x^4/4! - 24*x^5/5! + 59*x^6/6! - ...

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..200

EXAMPLE

x + 1/2!*x^2 + 4/3!*x^3 + 3/4!*x^4 + 33/5!*x^5 ...

MATHEMATICA

CoefficientList[Series[-Log[Sech[x]-Log[x+1]], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Nov 12 2016 *)

CROSSREFS

Sequence in context: A211364 A099438 A002178 * A161000 A220363 A120078

Adjacent sequences:  A013555 A013556 A013557 * A013559 A013560 A013561

KEYWORD

nonn

AUTHOR

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

EXTENSIONS

Offset and another leading 1 from R. J. Mathar, Dec 22 2011

a(0)=0 prepended by Vaclav Kotesovec, Nov 12 2016

STATUS

approved

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Last modified March 26 18:46 EDT 2017. Contains 284137 sequences.