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 A115189 #4 Sep 26 2012 04:24:13 %S A115189 1,40,466,4870,50053,516256,5371210,56422444,598180570,6395471992, %T A115189 68897550064,747270112390,8154207352045,89462667739360, %U A115189 986322436120690,10922076949690180,121428345789834430,1354895520307913680 %N A115189 Third diagonal (M=3) of triangle A115154 (called Y(3,1)). %F A115189 a(n)= A115154(n+2,n+1), n>=0. %F A115189 Recurrence: a(n)= b(n) - 6*b(n-1), with b(n):=A064063(n+3), n>=0. %F A115189 G.f.: ((-3+9*x +2*x^2) + 3*(1-6*x)*c(3*x))/((2+x)*x^2), with the o.g.f. c(x) of A000108 (Catalan). %e A115189 466 = a(2) = A064063(5) - 6*A064063(4) = 1606 - 6*190. %K A115189 nonn,easy %O A115189 0,2 %A A115189 _Wolfdieter Lang_, Feb 23 2006