A145074 Coefficient of x^(4^n) in Q(x)^(n+1) where Q(x) = Sum_{k>=0} (x^(4^k) + x^(2*4^k) + x^(3*4^k)).

1, 3, 12, 97, 885, 10386, 141295, 2218987, 39171564, 770029605, 16652860169, 393052609026, 10051000032099, 276818387211471, 8168772682637220, 257133140827399753

Offset

0,2

Links

Table of n, a(n) for n=0..15.

Prog

(PARI) {a(n, q=4)=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, A145075, A145076.

Sequence in context: A263801 A078124 A115245 * A374582 A162055 A067300

Adjacent sequences: A145071 A145072 A145073 * A145075 A145076 A145077

Keyword

more,nonn

Author

Paul D. Hanna, Oct 09 2008

Extensions

a(8)-a(10) from Sean A. Irvine, Mar 31 2011

a(11)-a(15) from Max Alekseyev, Dec 19 2011

Status

approved