Search: id:A005494 Results 1-1 of 1 results found. %I A005494 M3540 %S A005494 1,4,17,77,372,1915,10481,60814,372939,2409837,16360786,116393205, %T A005494 865549453,6713065156,54190360453,454442481041,3952241526188,35590085232519, %U A005494 331362825860749,3185554606447814,31581598272055879,322516283206446897 %N A005494 E.g.f.: exp(3*z+exp(z)-1). %C A005494 From expansion of falling factorials (binomial transform of A005493). %D A005494 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %D A005494 E. G. Whitehead, Jr., Stirling number identities from chromatic polynomials, J. Combin. Theory, A 24 (1978), 314-317. %H A005494 J. W. Layman, The Hankel Transform and Some of its Properties, J. Integer Sequences, 4 (2001), #01.1.5. %H A005494 N. J. A. Sloane, Transforms %F A005494 a(n) = Sum_{i=0..n} 3^(n-i)*B(i)*binomial(n,i) where B(n) = Bell numbers A000110(n). - Fred Lunnon, Aug 04 2007 %F A005494 a(n) = exp(-1)*sum(k=>0, (k+3)^(n)/k!) - Gerald McGarvey (Gerald.McGarvey(AT)comcast.net), Jun 03 2004. May be rewritten as a(n)=sum(k^n*(k-1)*(k-2)/k!,k=3..infinity)/ exp(1), which is a Dobinski-type relation for this sequence. - Karol A. Penson (penson(AT)lptl.jussieu.fr), Aug 18 2006 %F A005494 Define f_1(x),f_2(x),... such that f_1(x)=x^2*e^x, f_{n+1}(x)=diff(x*f_n(x), x), for n=2,3,.... Then a(n-1)=e^{-1}*f_n(1). - Milan R. Janjic (agnus(AT)blic.net), May 30 2008 %Y A005494 Cf. A000110, A005493. %Y A005494 Sequence in context: A151248 A104455 A123952 this_sequence A053486 A151249 A110307 %Y A005494 Adjacent sequences: A005491 A005492 A005493 this_sequence A005495 A005496 A005497 %K A005494 nonn %O A005494 0,2 %A A005494 N. J. A. Sloane (njas(AT)research.att.com), Simon Plouffe (simon.plouffe(AT)gmail.com) Search completed in 0.001 seconds