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A190961
a(n) = 3*a(n-1) - 7*a(n-2), with a(0)=0, a(1)=1.
2
0, 1, 3, 2, -15, -59, -72, 197, 1095, 1906, -1947, -19183, -43920, 2521, 315003, 927362, 577065, -4760339, -18320472, -21639043, 63326175, 341451826, 581072253, -646946023, -6008343840, -13496409359, 1569178803, 99182401922, 286562954145, 165412048981
OFFSET
0,3
FORMULA
G.f.: x/(1-3*x+7*x^2). - Philippe Deléham, Oct 11 2011
MATHEMATICA
LinearRecurrence[{3, -7}, {0, 1}, 50]
PROG
(PARI) x='x+O('x^30); concat([0], Vec(x/(1-3*x+7*x^2))) \\ G. C. Greubel, Jan 25 2018
(Magma) I:=[0, 1]; [n le 2 select I[n] else 3*Self(n-1) - 7*Self(n-2): n in [1..30]]; // G. C. Greubel, Jan 25 2018
CROSSREFS
Cf. A190958 (index to generalized Fibonacci sequences).
Sequence in context: A111999 A286947 A334559 * A346059 A126323 A292123
KEYWORD
sign,easy
AUTHOR
STATUS
approved