A012148 sec(tan(sin(x)))=1+1/2!*x^2+9/4!*x^4+153/6!*x^6+4337/8!*x^8...

1, 1, 9, 153, 4337, 188049, 11533497, 947095529, 100391885153, 13337306468001, 2164609458010345, 420395208704497849, 96150102074339268945, 25560738902667056074801, 7807205800461246020523161, 2710746396065167779192263433, 1059485323408621763305666629825

Offset

0,3

Links

Table of n, a(n) for n=0..16.

Mathematica

With[{nn=40}, Take[CoefficientList[Series[Sec[Tan[Sin[x]]], {x, 0, nn}], x]Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Dec 23 2011 *)

Crossrefs

Sequence in context: A113391 A045755 A009037 * A193540 A193543 A374854

Adjacent sequences: A012145 A012146 A012147 * A012149 A012150 A012151

Keyword

nonn

Author

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

Extensions

More terms from Harvey P. Dale, Dec 23 2011

Status

approved