A012478 sec(cos(x)*sin(x))=1+1/2!*x^2-11/4!*x^4-83/6!*x^6+10505/8!*x^8...

1, 1, -11, -83, 10505, 6009, -60553539, 2140355557, 1174906248337, -146823377897103, -55094515820657147, 17482899642565858461, 4900898798285366105753, -3664217968514770645784087

Offset

0,3

Links

Table of n, a(n) for n=0..13.

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sec[Cos[x]Sin[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Nov 09 2022 *)

Crossrefs

Sequence in context: A129077 A152582 A191003 * A239461 A330966 A026783

Adjacent sequences: A012475 A012476 A012477 * A012479 A012480 A012481

Keyword

sign

Author

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

Status

approved