# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a372016 Showing 1-1 of 1 %I A372016 #6 Apr 16 2024 10:23:07 %S A372016 1,2,0,6,-2,38,-32,314,-436,3014,-5732,31954,-74934,363642,-983868, %T A372016 4360230,-13021586,54374950,-173933428,698713298,-2345075002, %U A372016 9189017010,-31903354068,123070336590,-437701811100,1672475509274,-6052049207112,22998585552814 %N A372016 G.f. A(x) satisfies A(x) = ( 1 + 4*x/(1 - x*A(x)) )^(1/2). %F A372016 a(n) = Sum_{k=0..n} 4^k * binomial(n/2-k/2+1/2,k) * binomial(n-1,n-k)/(n-k+1). %o A372016 (PARI) a(n) = sum(k=0, n, 4^k*binomial(n/2-k/2+1/2, k)*binomial(n-1, n-k)/(n-k+1)); %Y A372016 Cf. A372002. %K A372016 sign %O A372016 0,2 %A A372016 _Seiichi Manyama_, Apr 15 2024 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE