A097322 - OEIS

%I #3 Apr 30 2014 01:28:34

%S 1,4,1,1,4,1,1,4,1,11,4,1,1,4,11,1,4,31,1,44,29,1,4,1,11,4,29,1,4,11,

%T 1,4,31,1,1276,1,41,4,1,11,116,1,1,292,11,1,4,31,127571,44,1,1,4,1,

%U 319,4,41,1,4,11,1,4,899,1,44,1,1,4,29,11,4,1,1,4,583,1,4756,361429

%N (2n)! divided by denominator of Taylor expansion of exp(cos(x)-1).

%o (PARI) a(n)=(2*n)!/denominator(polcoeff(Ser(exp(cos(x)-1)),2*n))

%Y Equals A010050(n) / A047690(n).

%Y Cf. A005046.

%K nonn,easy

%O 1,2

%A _Ralf Stephan_, Aug 08 2004