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A077873
Expansion of (1-x)^(-1)/(1-x+x^2+2*x^3).
1
1, 2, 2, -1, -6, -8, 1, 22, 38, 15, -66, -156, -119, 170, 602, 671, -270, -2144, -3215, -530, 6974, 13935, 8022, -19860, -55751, -51934, 43538, 206975, 267306, -26744, -707999, -1215866, -454378, 2177487, 5063598, 3794868, -5623703, -19545766, -21511798, 9281375, 69884706, 103626928
OFFSET
0,2
FORMULA
a(n) = 2*a(n-4)-a(n-3)-2*a(n-2)+2*a(n-1). - Robert Israel, May 19 2014
MAPLE
N:= 100; # to get a(n) for n <= N
A:= <<0, 1, 0, 0>|<0, 0, 1, 0>|<0, 0, 0, 1>|<2, -1, -2, 2>>:
seq(<1|2|2|-1> . A^j . <1, 0, 0, 0>, j=0..N); # Robert Israel, May 19 2014
CROSSREFS
Sequence in context: A222073 A343847 A135880 * A123305 A118024 A184184
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Nov 17 2002
STATUS
approved