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A371586
G.f. satisfies A(x) = ( 1 + x*A(x)^2 * (1 + x*A(x)^2)^2 )^2.
0
1, 2, 13, 106, 986, 9898, 104535, 1144630, 12876908, 147937396, 1728352171, 20471245898, 245254954252, 2966792716710, 36186910210761, 444559817944096, 5495828249436652, 68318636646858588, 853455362282694440, 10708603125245767280, 134897492549870974674
OFFSET
0,2
FORMULA
If g.f. satisfies A(x) = ( 1 + x*A(x)^(t/r) * (1 + x*A(x)^(u/r))^s )^r, then a(n) = r * Sum_{k=0..n} binomial(t*k+u*(n-k)+r,k) * binomial(s*k,n-k)/(t*k+u*(n-k)+r).
PROG
(PARI) a(n, r=2, s=2, t=4, u=4) = r*sum(k=0, n, binomial(t*k+u*(n-k)+r, k)*binomial(s*k, n-k)/(t*k+u*(n-k)+r));
CROSSREFS
Cf. A367282.
Sequence in context: A371583 A083062 A204261 * A371574 A127746 A199124
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Mar 28 2024
STATUS
approved