0,3

1 + 4*q + 12*q^2 + 36*q^3 + 100*q^4 + 284*q^5 + 780*q^6 + 2172*q^7 + 5916*q^8 + 16268*q^9 + ... / 1 + 4*q + 4*q^2 + 4*q^4 + 8*q^5 + 4*q^8 + 4*q^9 + ... = 1 + 8*q^2 + 4*q^3 + 48*q^4 + 68*q^5 + 284*q^6 + 684*q^7 + 1816*q^8 + 5608*q^9 + ...

Cf. A001411, A004018.

Sequence in context: A160411 A033473 A082682 this_sequence A112584 A112546 A112583

Adjacent sequences: A046103 A046104 A046105 this_sequence A046107 A046108 A046109

nonn

N. J. A. Sloane (njas(AT)research.att.com), based on a suggestion of Maurice Craig (Maurice.D.Craig(AT)BHPBilliton.com), May 11 2003