A145075 Coefficient of x^(5^n) in Q(x)^(n+1), where Q(x) = Sum_{k>=0} (x^(5^k) + x^(2*5^k) + x^(3*5^k) + x^(4*5^k)).

1, 4, 18, 172, 1881, 25644, 411488, 7581792, 157296141, 3630709734, 92225760033, 2556393882912, 76774488792326, 2483261807354874

Offset

0,2

Links

Table of n, a(n) for n=0..13.

Prog

(PARI) {a(n, q=5)=local(Q=sum(j=0, n, (x^(q^j)-x^(q*q^j))/(1-x^(q^j)+O(x^(q^n+1))))); polcoeff(Q^(n+1), q^n)}

Crossrefs

Cf. A007178, A145073, A145074, A145076.

Sequence in context: A367486 A156870 A240317 * A058924 A260970 A154731

Adjacent sequences: A145072 A145073 A145074 * A145076 A145077 A145078

Keyword

more,nonn

Author

Paul D. Hanna, Oct 09 2008

Extensions

a(7)-a(13) from Max Alekseyev, Dec 19 2011

Status

approved