# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a102814 Showing 1-1 of 1 %I A102814 #5 Nov 06 2019 17:50:48 %S A102814 1,1,2,4,11,30,103,354,1440,5911,27651,131062,690543,3693765,21585068, %T A102814 128165652,820859645,5343318222,37155889171,262577578134, %U A102814 1967281479508,14975397597557,120122032987319,978625889818014,8359402026954939,72495015037575673,656446920912518700 %N A102814 a(-1) = 1, a(n) = Sum_{k=0..n} A034851(n,k)*a(k-1) where A034851(n,k) are entries in Losanitsch's triangle. %H A102814 Andrew Howroyd, Table of n, a(n) for n = -1..200 %o A102814 (PARI) \\ here T(n,k) is A034851(n,k). %o A102814 T(n, k) = {(1/2)*(binomial(n, k) + binomial(n%2, k%2) * binomial(n\2, k\2))} %o A102814 seq(n)={my(a=vector(n+1)); a[1]=1; for(n=1, n, a[n+1]=sum(k=1, n, a[k]*T(n-1,k-1))); a} \\ _Andrew Howroyd_, Nov 06 2019 %Y A102814 Cf. A034851. %K A102814 nonn %O A102814 -1,3 %A A102814 _Gerald McGarvey_, Feb 26 2005 %E A102814 Terms a(12) and beyond from _Andrew Howroyd_, Nov 06 2019 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE