login
A354063
Product_{n>=1} 1 / (1 - x^(2*n))^(a(n)/(2*n)!) = cos(x).
6
-1, 4, 104, 1408, 354944, -21642752, 6204652544, 68669145088, 47215125069824, -78465506362130432, 51085990673656315904, -6994033618612756938752, 15510963121850795776016384, -7220202338641080038690127872, -7469518701197092988127633473536, 11962377309169877924807975108608
OFFSET
1,2
FORMULA
E.g.f.: Sum_{k>=1} mu(k) * log(cos(x^k)) / k (even powers only).
MATHEMATICA
nmax = 32; Take[CoefficientList[Series[Sum[MoebiusMu[k] Log[Cos[x^k]]/k, {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]!, {1, -1, 2}] // Rest
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, May 16 2022
STATUS
approved