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A134270
a(n)=2a(n-1)+a(n-2)-4a(n-4).
1
1, 1, 3, 7, 13, 29, 59, 119, 245, 493, 995, 2007, 4029, 8093, 16235, 32535, 65189, 130541, 261331, 523063, 1046701, 2094301, 4189979, 8382007, 16767189, 33539181, 67085635, 134182423, 268381725, 536789149, 1073617483, 2147294423, 4294679429, 8589496685
OFFSET
0,3
FORMULA
O.g.f.: (1+x)*x/(2*x^3+x^2-1)-1/(2*x-1) . a(n) = -|A078028(n-1)| + 2^n . - R. J. Mathar, Feb 01 2008
MATHEMATICA
LinearRecurrence[{2, 1, 0, -4}, {1, 1, 3, 7}, 40] (* Harvey P. Dale, Jan 16 2013 *)
CROSSREFS
Sequence in context: A284542 A283323 A260022 * A091565 A025249 A147098
KEYWORD
nonn
AUTHOR
Paul Curtz, Jan 30 2008
EXTENSIONS
More terms from Harvey P. Dale, Jan 16 2013
STATUS
approved