Search: id:A052882 Results 1-1 of 1 results found. %I A052882 %S A052882 0,1,2,9,52,375,3246,32781,378344,4912515,70872610,1124723193, %T A052882 19471590876,365190378735,7376016877334,159620144556645, %U A052882 3684531055645648,90366129593683035,2346673806524446218 %N A052882 A simple grammar: rooted ordered set partitions. %C A052882 Recurrence (see Mathematica line) is similar to that for Genocchi numbers A001469 - Wouter Meeussen (wouter.meeussen(AT)pandora.be), Jan 09 2001 %C A052882 Stirling transform of A024167(n)=[1,1,5,14,94,...] is a(n)=[1,2,9,52, 375,...]. - Michael Somos Mar 04 2004 %C A052882 Stirling transform of a(n)=[0,2,9,52,375,...] is A087301(n+1)=[0,2,3, 20,...]. - Michael Somos Mar 04 2004 %H A052882 INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 855 %H A052882 S. Ramanujan, Notebook entry %F A052882 E.g.f.: x/(2-exp(x)). %F A052882 a(n) = (1/2)*sum(k=0, n-1, B_k*A000629(k)*binomial(n, k)) where B_k is the k-th Bernoulli number. - Benoit Cloitre (benoit7848c(AT)orange.fr), Oct 19 2005 %p A052882 spec := [S,{C=Sequence(B),B=Set(Z,1 <= card),S=Prod(Z,C)},labeled]: seq(combstruct[count](spec, size=n), n=0..20); %p A052882 with(combinat):a:=n->sum(sum(sum((-1)^(k-i)*binomial(k, i)*i^n, i=0..n), k=0..n),m=0..n): seq(a(n), n=-1..17); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 03 2007 %t A052882 a[1] := 1; a[n_] := a[n]=Sum[ Binomial[n, m] a[ n-m], {m, 1, n-1}] %o A052882 (PARI) a(n)=if(n<0,0,n!*polcoeff(subst(x/(1-y),y,exp(x+x*O(x^n))-1),n)) %Y A052882 Cf. A001469. %Y A052882 For n>0, a(n)=n*A000670(n). %Y A052882 Sequence in context: A069271 A006152 A143508 this_sequence A143922 A110322 A161631 %Y A052882 Adjacent sequences: A052879 A052880 A052881 this_sequence A052883 A052884 A052885 %K A052882 easy,nonn %O A052882 0,3 %A A052882 encyclopedia(AT)pommard.inria.fr, Jan 25 2000 Search completed in 0.004 seconds