A013476 Coefficient of x^(4*n+2) in e.g.f. arcsinh(cos(x) - cosh(x)).

-2, 118, -267122, 3801437638, -188997287445602, 24300893634392843158, -6725983870126469414416082, 3540538990952328979449335176678, -3241779510843677923729210281115258562

Offset

0,1

Links

Robert Israel, Table of n, a(n) for n = 0..112

Example

-(2/2!)*x^2 + (118/6!)*x^6 - (267122/10!)*x^10 + (3801437638/14!)*x^14 - ...

Maple

S:= series(arcsinh(cos(x)-cosh(x)), x, 103):
seq(coeff(S, x, 4*n+2)*(4*n+2)!, n=0..25); # Robert Israel, Aug 16 2018

Crossrefs

Sequence in context: A013470 A013511 A013507 * A103851 A024030 A221231

Adjacent sequences: A013473 A013474 A013475 * A013477 A013478 A013479

Keyword

sign

Author

Patrick Demichel

Extensions

Missing a(0)=-2 inserted, more terms, and title improved by Sean A. Irvine, Aug 07 2018

Status

approved