A370799 Expansion of (1/x) * Series_Reversion( x/(x+1/(1-x+x^2)) ).
1, 2, 4, 7, 7, -18, -152, -648, -2076, -5006, -6442, 17866, 178102, 851516, 3004912, 7956103, 11925503, -24636636, -298702394, -1532903353, -5722053149, -16080843014, -27090920172, 37370086052, 584086176148, 3182365757908, 12407797520932, 36551266481968
Offset: 0
Keywords
Programs
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PARI
my(N=30, x='x+O('x^N)); Vec(serreverse(x/(x+1/(1-x+x^2)))/x)
Formula
a(n) = Sum_{k=0..n} binomial(n,k) * b(k), where g.f. B(x) = Sum_{k>=0} b(k)*x^k satisfies B(x) = (1/x) * Series_Reversion( x*(1-x+x^2) ).