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A091097
Expansion of (1+6x-60x^2)/((1-6x)(1+6x)).
0
1, 6, -24, 216, -864, 7776, -31104, 279936, -1119744, 10077696, -40310784, 362797056, -1451188224, 13060694016, -52242776064, 470184984576, -1880739938304, 16926659444736, -67706637778944, 609359740010496, -2437438960041984
OFFSET
0,2
COMMENTS
a(0)=1, a(2n-1)=k^(2n-1), a(2n)=(2-k)k^(2n-1), k=6, G.f.: (1+kx+(2-2k)kx^2)/((1-kx)(1+kx)), k=6.
FORMULA
a(n)=6^n/6+(-5)(-6)^n/6+10*0^n/6
CROSSREFS
Sequence in context: A372136 A320944 A277985 * A231317 A223105 A112675
KEYWORD
easy,sign
AUTHOR
Paul Barry, Dec 19 2003
STATUS
approved