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URL: https://oeis.org/A371517

⇱ A371517 - OEIS


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A371517
G.f. A(x) satisfies A(x) = (1 + x*A(x) / (1-x))^4.
6
1, 4, 26, 188, 1459, 11892, 100444, 871528, 7722557, 69590628, 635807180, 5876094308, 54836925779, 516029817620, 4891147100886, 46653935716492, 447490869463145, 4313492172957396, 41763413498670702, 405968522259130636, 3960526930400038404
OFFSET
0,2
FORMULA
a(n) = 4 * Sum_{k=0..n} binomial(n-1,n-k) * binomial(4*k+3,k)/(3*k+4) = Sum_{k=0..n} binomial(n-1,n-k) * binomial(4*k+4,k)/(k+1).
G.f.: A(x) = B(x)^4 where B(x) is the g.f. of A349331.
PROG
(PARI) a(n) = 4*sum(k=0, n, binomial(n-1, n-k)*binomial(4*k+3, k)/(3*k+4));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Mar 26 2024
STATUS
approved