%I A056541
%S A056541 0,1,5,31,249,2491,29893,418503,6696049,120528883,2410577661,
%T A056541 53032708543,1272785005033,33092410130859,926587483664053,
%U A056541 27797624509921591,889523984317490913,30243815466794691043
%N A056541 a(n) = 2n*a(n-1) + 1 with a(0)=0.
%F A056541 a(n) =floor[(sqrt(e)-1)*2^n*n! ] =A010844(n)-A000165(n)
%F A056541 a(n) = Sum[P(n, k) * 2^k {k=0 to n-1}] - Ross La Haye (rlahaye(AT)new.rr.com), 
               Sep 15 2004
%e A056541 a(3)=2*3*a(2)+1=6*5+1=31
%t A056541 s=0;lst={s};Do[s+=s++n;AppendTo[lst, Abs[s]], {n, 1, 5!, 2}];lst [From 
               Vladimir Orlovsky (4vladimir(AT)gmail.com), Oct 23 2008]
%Y A056541 Cf. A002627.
%Y A056541 Sequence in context: A082579 A024451 A046852 this_sequence A126121 A167137 
               A000556
%Y A056541 Adjacent sequences: A056538 A056539 A056540 this_sequence A056542 A056543 
               A056544
%K A056541 easy,nonn
%O A056541 0,3
%A A056541 Henry Bottomley (se16(AT)btinternet.com), Jun 20 2000
%E A056541 More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jul 04 2000