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Expansion of (1/x) * Series_Reversion( x*(1-x)^4/(1+x) ).
3

%I #13 Sep 20 2023 10:00:29

%S 1,5,39,365,3772,41491,476410,5644477,68493324,846937140,10633195119,

%T 135185288475,1736883987836,22516798984946,294169295918996,

%U 3869084306851933,51189853304834940,680816769653570044,9097058255214149068,122064057533865334100

%N Expansion of (1/x) * Series_Reversion( x*(1-x)^4/(1+x) ).

%H Seiichi Manyama, <a href="/A365765/b365765.txt">Table of n, a(n) for n = 0..865</a>

%F a(n) = (1/(n+1)) * Sum_{k=0..n} binomial(n+1,k) * binomial(5*n-k+3,n-k) = (1/(n+1)) * Sum_{k=0..n} binomial(4*n+k+3,k) * binomial(n+1,n-k).

%o (PARI) a(n) = sum(k=0, n, binomial(n+1, k)*binomial(5*n-k+3, n-k))/(n+1);

%Y Cf. A003169, A006318, A365764, A365766.

%Y Cf. A365752.

%K nonn

%O 0,2

%A _Seiichi Manyama_, Sep 18 2023