A366083 Expansion of (1/x) * Series_Reversion( x*(1-x)^4/(1-x-x^2) ).
1, 3, 14, 78, 478, 3109, 21063, 146997, 1049302, 7624330, 56198481, 419155136, 3157356819, 23984387314, 183519131353, 1413099475142, 10941294442694, 85132006090350, 665294548097852, 5219591907202092, 41095469624286421, 324595783790966343
Offset: 0
Keywords
Links
- Seiichi Manyama, Table of n, a(n) for n = 0..1000
Programs
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PARI
a(n) = sum(k=0, n\2, (-1)^k*binomial(n+1, k)*binomial(4*n-k+2, n-2*k))/(n+1);
Formula
a(n) = (1/(n+1)) * Sum_{k=0..floor(n/2)} (-1)^k * binomial(n+1,k) * binomial(4*n-k+2,n-2*k).