0,2
Next term, a(8), has 126 digits.
Table of n, a(n) for n=0..7.
a(0) = [x] (1+x) = 1;
a(1) = [x^2] (1+x)^2*(1+x^2) = 2;
a(2) = [x^4] (1+x)^4*(1+x^2)^2*(1+x^4) = 15;
a(3) = [x^8] (1+x)^8*(1+x^2)^4*(1+x^4)^2*(1+x^8) = 1024;
a(4) = [x^16] (1+x)^16*(1+x^2)^8*(1+x^4)^4*(1+x^8)^2*(1+x^16) = 7048181.
(PARI) {a(n)=polcoeff(prod(i=0, n, (1 + x^(2^i) +x*O(x^(2^n)))^(2^(n-i))), 2^n)}
Cf. A132318, A132316.
Sequence in context: A007542 A090604 A007467 * A068409 A096232 A193869
Adjacent sequences: A132314 A132315 A132316 * A132318 A132319 A132320
nonn
Paul D. Hanna, Aug 19 2007
approved
