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A134812
a(n) = 2a(n-2) + 4a(n-3), n >= 3.
2
0, 1, -1, 1, 2, -2, 8, 4, 8, 40, 32, 112, 224, 352, 896, 1600, 3200, 6784, 12800, 26368, 52736, 103936, 210944, 418816, 837632, 1681408, 3350528, 6713344, 13426688, 26828800, 53706752, 107364352, 214728704, 429555712, 858914816, 1718026240, 3436052480, 6871711744, 13744209920
OFFSET
0,5
FORMULA
G.f. x*(-1 + x + x^2) / ( (2*x-1)*(2*x^2 + 2*x + 1) ). - R. J. Mathar, Aug 11 2012
20*a(n) = 2^n - 6*A078069(n), n>0. - R. J. Mathar, Aug 11 2012
CROSSREFS
Cf. A038521.
Sequence in context: A331333 A120399 A144816 * A144847 A143625 A003612
KEYWORD
sign,easy
AUTHOR
Paul Curtz, Jan 28 2008
EXTENSIONS
More terms from Joshua Zucker, Feb 23 2008
STATUS
approved