%I A006348 M3609
%S A006348 0,1,4,25,174,1393,12536,125361,1378970,16547641,215119332,3011670649,
%T A006348 45175059734,722800955745,12287616247664,221177092457953,4202364756701106
%N A006348 a(n) = (n+2)*a(n-1) + (-1)^n.
%D A006348 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%p A006348 a:=n->n!*sum((-1)^k/k!, k=4..n): seq(a(n), n=3..19); - Zerinvary Lajos 
               (zerinvarylajos(AT)yahoo.com), May 25 2007
%Y A006348 Sequence in context: A034494 A084210 A093683 this_sequence A051820 A166697 
               A054368
%Y A006348 Adjacent sequences: A006345 A006346 A006347 this_sequence A006349 A006350 
               A006351
%K A006348 nonn,easy
%O A006348 1,3
%A A006348 N. J. A. Sloane (njas(AT)research.att.com).