A366086 - OEIS

%I #8 Sep 28 2023 12:07:53

%S 1,-1,1,-1,0,4,-14,34,-65,89,-29,-331,1464,-4148,9010,-14366,9761,

%T 38895,-215015,674423,-1594973,2829973,-2732465,-4812567,36116257,

%U -124617681,316617081,-611942761,735416371,488457845,-6451021289,24658985649,-66990721867,139346533259

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

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

%o (PARI) a(n) = sum(k=0, n\4, (-1)^(n-k)*binomial(n+1, k)*binomial(n-k+1, n-4*k))/(n+1);

%Y Cf. A366087, A366088, A366089, A366090.

%Y Cf. A366051, A366057.

%K sign

%O 0,6

%A _Seiichi Manyama_, Sep 28 2023