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Denominators of coefficients in (1+x)^(1+x) power series.
1

%I #7 Dec 31 2015 11:32:17

%S 1,1,1,2,3,12,40,120,2520,5040,10080,5040,19958400,19958400,259459200,

%T 518918400,2179457280,4358914560,1235025792000,3705077376000,

%U 422378820864000,52797352608000,120679663104000,844757641728000

%N Denominators of coefficients in (1+x)^(1+x) power series.

%t Denominator[CoefficientList[Series[(1+x)^(1+x),{x,0,30}],x]] (* _Harvey P. Dale_, Dec 31 2015 *)

%o (PARI) a(n)=denominator(polcoeff((1+x)^(1+x)+O(x^(n+1)),n))

%K frac,nonn

%O 0,4

%A _Benoit Cloitre_, Apr 30 2003