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A367114
G.f. satisfies A(x) = 1 + 2*x*A(x) + x^4*A(x)^4.
1
1, 2, 4, 8, 17, 42, 124, 408, 1380, 4616, 15184, 49568, 162518, 539580, 1818184, 6203088, 21339916, 73776024, 255853744, 889678688, 3102779785, 10856555130, 38115293308, 134243564056, 474159194316, 1678926445272, 5957812156144, 21183679310048
OFFSET
0,2
FORMULA
a(n) = Sum_{k=0..floor(n/4)} 2^(n-4*k) * binomial(n,4*k) * A002293(k).
PROG
(PARI) a(n) = sum(k=0, n\4, 2^(n-4*k)*binomial(n, 4*k)*binomial(4*k, k)/(3*k+1));
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Seiichi Manyama, Nov 05 2023
STATUS
approved