This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A115153 #10 May 22 2013 05:47:05 %S A115153 1,127,1665,16255,141441,1163135,9273473,72613759,562430081, %T A115153 4327407487,33161347201,253517365119,1935665528961,14771256557439, %U A115153 112715410440321,860346088685439,6570305359184001,50209563856600959,383989436028813441 %N A115153 Sixth diagonal (M=6) sequence of triangle A113647, called Y(2,1). %H A115153 Vincenzo Librandi, <a href="/A115153/b115153.txt">Table of n, a(n) for n = 0..200</a> %F A115153 a(n)= A113647(n+5, n+1), n>=0. %F A115153 G.f.: ((-2 + 16*x - 24*x^2 + x^5) + 2*(1 - 10*x + 24*x^2 - 8*x^3)*c(2*x))/((x^5)*(1+x)), with the o.g.f. c(x):=(1-sqrt(1-4*x))/(2*x) of A000108 (Catalan numbers). %F A115153 Recurrence: (n-1)*(n+6)*a(n) = (7*n^2+23*n+30)*a(n-1) + 4*(n+2)*(2*n+3)*a(n-2). - _Vaclav Kotesovec_, Oct 19 2012 %F A115153 a(n) ~ 7*2^(3n+13)/(9*sqrt(Pi)*n^(3/2)). - _Vaclav Kotesovec_, Oct 19 2012 %t A115153 CoefficientList[Series[((-2+16*x-24*x^2+x^5)+2*(1-10*x+24*x^2-8*x^3)*(1-Sqrt[1-8*x])/(4*x))/((x^5)*(1+x)), {x, 0, 20}], x] (* _Vaclav Kotesovec_, Oct 19 2012 *) %K A115153 nonn,easy %O A115153 0,2 %A A115153 _Wolfdieter Lang_, Jan 13 2006