A199802 G.f.: 1/(1-2*x+2*x^2-x^3+x^4).

1, 2, 2, 1, -1, -4, -7, -8, -5, 3, 15, 27, 32, 22, -8, -55, -104, -128, -95, 17, 200, 399, 510, 405, -11, -721, -1525, -2024, -1708, -172, 2573, 5806, 8002, 7137, 1503, -9072, -22015, -31520, -29585, -9073, 31519, 83119, 123712, 121778, 47732, -107499, -312396, -483840, -498119, -233455, 357884, 1168399, 1885694, 2025929, 1090985, -1152593

Offset: 0

Author

N. J. A. Sloane, Nov 10 2011

Keywords

• sign
• easy

Links

• Hirschhorn, Michael D., Non-trivial intertwined second-order recurrence relations, Fibonacci Quart. 43 (2005), no. 4, 316-325. See G_n.
• Index entries for linear recurrences with constant coefficients, signature (2,-2,1,-1).

Crossrefs

The main sequences mentioned in the Hisrchhorn paper are A199802, A199803, A199744, A199804, A077961, A199805.

Programs

Mathematica

CoefficientList[Series[1/(1-2x+2x^2-x^3+x^4),{x,0,60}],x] (* or *) LinearRecurrence[ {2,-2,1,-1},{1,2,2,1},60] (* Harvey P. Dale, May 11 2022 *)