A121564 - OEIS

%I #4 Mar 30 2012 18:40:38

%S 1,2,18,288,180000,1620000,190591380000,780662292480000,

%T 46097327708651520000,28810829817907200000000,

%U 747278726094210559615027200000000,747278726094210559615027200000000

%N Denominator of Sum[i=1..n] i!/(i^i).

%C Numerators are A121563. Limit as n approaches infinity of A121563(n)/A121564(n) = 1.879853862175258533486306145... whose decimal expansion is A094082.

%F Denominator of Sum[i=1..n] i!/(i^i) A000142(i)/A000312(i).

%e a(1) = 1/1 = 1.

%e a(2) = 3/2 = 1.5

%e a(3) = 31/18 = 1.72222222222.

%e a(4) = 523/288 = 1.81597222222.

%e a(5) = 333787/180000 = 1.85437222222.

%Y Cf. A000142, A000312, A055775, A094082.

%K easy,frac,nonn

%O 1,2

%A _Jonathan Vos Post_, Aug 07 2006