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A012003
E.g.f. cos(log(cos(x))), even powers only.
2
1, 0, -3, -30, -483, -12660, -492063, -26407290, -1854592743, -162954226920, -17150991170523, -2051454240374550, -254425037609483403, -24186909676571913180, 3098088521295623020617
OFFSET
0,3
FORMULA
For n>1, a(n) appears to be divisible by 3, and the highest exponent of 2 in a(2m+1) seems to be A001511(m). - Ralf Stephan, Aug 14 2013
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Cos[Log[Cos[x]]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Aug 29 2011 *)
CROSSREFS
Sequence in context: A276356 A375393 A377575 * A164945 A354252 A354261
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved