Search: id:A019583 Results 1-1 of 1 results found. %I A019583 %S A019583 0,0,1,24,162,640,1875,4536,9604,18432,32805,55000,87846, %T A019583 134784,199927,288120,405000,557056,751689,997272,1303210, %U A019583 1680000,2139291,2693944,3358092,4147200,5078125,6169176 %N A019583 n*(n-1)^4/2. %C A019583 a(n)=n(n-1)^4/2 is half the number of colorings of 5 points on a line with n colors. - Ron Hardin (rhhardin(AT)att.net), Feb 23 2002 %C A019583 A019583[n+2]=denom((1/2)*n^5+3*n^4+7*n^3+8*n^2+(9/2)*n+1) [From Stephen Crowley (crow(AT)crowlogic.net), Jun 28 2009] %F A019583 sum(1/A019583[j],j=2..infinity)=hypergeom([1, 1, 1, 1, 1], [ 2, 2, 2, 3], 1)=-2+2*Zeta(2)-2*Zeta(3)+2*Zeta(4) [From Stephen Crowley (crow(AT)crowlogic.net), Jun 28 2009] %p A019583 with(combinat):a:=n->sum(sum(sum(binomial(n+2,2), j=0..n), k=0..n),m=0..n): seq(a(n), n=-2..25); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 30 2007 %p A019583 a:=n->sum(n^2*sum(n, k=0..n-1), k=0..n)/2:seq(a(n), n=-1...26); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Aug 01 2008 %p A019583 a:=n->sum(n^2*sum(n, k=0..n-1), k=0..n)/2:seq(a(n), n=-1...26); [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Aug 09 2008] %Y A019583 Sequence in context: A125334 A126492 A136380 this_sequence A087887 A166756 A165187 %Y A019583 Adjacent sequences: A019580 A019581 A019582 this_sequence A019584 A019585 A019586 %K A019583 nonn %O A019583 0,4 %A A019583 N. J. A. Sloane (njas(AT)research.att.com). %E A019583 hypergeometric zeta formula [From Stephen Crowley (crow(AT)crowlogic.net), Jun 28 2009] Search completed in 0.001 seconds