A199931 Trisection 1 of A199803.

-1, 2, 4, -15, -2, 79, -88, -294, 815, 488, -4769, 3438, 20080, -42527, -49666, 278943, -93220, -1308634, 2103343, 4067664, -15799793, -1126550, 82089836, -96324543, -299451394, 864290495, 454552096, -4979131422, 3870112831, 20615805880, -45400053553, -48829731594, 292575692408

Offset: 0

Author

N. J. A. Sloane, Nov 12 2011

Keywords

• sign
• easy

Links

• Colin Barker, Table of n, a(n) for n = 0..1000
• Hirschhorn, Michael D., Non-trivial intertwined second-order recurrence relations, Fibonacci Quart. 43 (2005), no. 4, 316-325. See p. 324.
• Index entries for linear recurrences with constant coefficients, signature (-1,-5,1,-1).

Programs

Mathematica

CoefficientList[ Series[(-1 +x +x^2)/(1 +x +5x^2 -x^3 +x^4), {x, 0, 30}], x] (* or *)
LinearRecurrence[{-1, -5, 1, -1}, {-1, 2, 4, -15}, 30] (* Robert G. Wilson v, Dec 27 2017 *)

PARI

Vec(-(1 - x - x^2) / (1 + x + 5*x^2 - x^3 + x^4) + O(x^40)) \\ Colin Barker, Dec 27 2017

Formula

From Colin Barker, Dec 27 2017: (Start)

G.f.: -(1 - x - x^2) / (1 + x + 5*x^2 - x^3 + x^4).

a(n) = -a(n-1) - 5*a(n-2) + a(n-3) - a(n-4) for n>3.

(End)