login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A199931
Trisection 1 of A199803.
1
-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
0,2
LINKS
Hirschhorn, Michael D., Non-trivial intertwined second-order recurrence relations, Fibonacci Quart. 43 (2005), no. 4, 316-325. See p. 324.
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)
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 *)
PROG
(PARI) Vec(-(1 - x - x^2) / (1 + x + 5*x^2 - x^3 + x^4) + O(x^40)) \\ Colin Barker, Dec 27 2017
CROSSREFS
Sequence in context: A359569 A147870 A347790 * A163361 A278873 A278901
KEYWORD
sign,easy
AUTHOR
N. J. A. Sloane, Nov 12 2011
STATUS
approved