1,2
G.F. is (-18x + 48x^2) / (1 - 12x + 36x^4 + 47x^2 - 72x^3).
a(n) = 6^n - 3*2^n - 3^n + 3
Sequence in context: A099196 A041618 A055915 * A125381 A126539 A161499
Adjacent sequences: A071536 A071537 A071538 * A071540 A071541 A071542
nonn
Sharon Sela (sharonsela(AT)hotmail.com), Jun 02 2002