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A199803
G.f.: 1/(1 + x - x^2 - x^3 + x^4).
5
1, -1, 2, -2, 2, -1, -1, 4, -8, 12, -15, 15, -10, -2, 22, -49, 79, -104, 112, -88, 17, 111, -294, 510, -710, 815, -721, 316, 488, -1708, 3233, -4769, 5806, -5634, 3438, 1503, -9505, 20080, -31520, 40592, -42527, 31519, -1934, -49666, 121778, -204897, 278943, -312396, 264664, -93220, -233455, 717295, -1308634, 1885694, -2243578, 2103343, -1152593, -873336
OFFSET
0,3
LINKS
Michael D. Hirschhorn, Non-trivial intertwined second-order recurrence relations, Fibonacci Quart. 43 (2005), no. 4, 316-325. See H_n.
FORMULA
a(n) = -a(n-1) + a(n-2) + a(n-3) - a(n-4) for n > 3. - Taras Goy, Dec 24 2019
MATHEMATICA
CoefficientList[Series[1/(1 + x - x^2 - x^3 + x^4), {x, 0, 57}], x] (* Michael De Vlieger, Dec 24 2019 *)
LinearRecurrence[{-1, 1, 1, -1}, {1, -1, 2, -2}, 60] (* Harvey P. Dale, Jan 17 2021 *)
CROSSREFS
Sequence in context: A242775 A079562 A338664 * A304197 A348768 A210673
KEYWORD
sign,easy
AUTHOR
N. J. A. Sloane, Nov 10 2011
STATUS
approved