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A110043 a(1) = 2; for n>1, a(n) = n*a(n-1) + (-1)^n. 1

%I

%S 2,5,14,57,284,1705,11934,95473,859256,8592561,94518170,1134218041,

%T 14744834532,20642783449,3096415251734,49542644027745,842224948471664,

%U 15160049072489953,288040932377309106,5760818647546162121

%N a(1) = 2; for n>1, a(n) = n*a(n-1) + (-1)^n.

%C A000166 and A001120 have a similar recurrence.

%C a(n) - (n-1)*(a(n-1)+a(n-2)),n>2 [From _Gary Detlefs_, Apr 11 2010]

%F a(n) = A001120(n) + n! = A000166(n) + 2*n!.

%F a(n) = 2*n! + floor((n!+1)/e) [From _Gary Detlefs_, Apr 11 2010]

%K nonn,easy

%O 1,1

%A _Philippe Deléham_, Sep 04 2005

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Last modified April 21 04:56 EDT 2019. Contains 322310 sequences. (Running on oeis4.)