A199803 G.f.: 1/(1 + x - x^2 - x^3 + x^4).

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 De Vlieger, Table of n, a(n) for n = 0..8475

Michael D. Hirschhorn, Non-trivial intertwined second-order recurrence relations, Fibonacci Quart. 43 (2005), no. 4, 316-325. See H_n.

Index entries for linear recurrences with constant coefficients, signature (-1,1,1,-1).

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

Adjacent sequences: A199800 A199801 A199802 * A199804 A199805 A199806

Keyword

sign,easy

Author

N. J. A. Sloane, Nov 10 2011

Status

approved