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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (3, -7).

FORMULA

a(n) = (1/19*I)*sqrt(19)*((3/2-(1/2*I) *sqrt(19))^n-(3/2+(1/2*I)*sqrt(19))^n). - Paolo P. Lava, Jun 01 2011

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: A133932 A111999 A286947 * A126323 A292123 A084886

Adjacent sequences:  A190958 A190959 A190960 * A190962 A190963 A190964

KEYWORD

sign

AUTHOR

Vladimir Joseph Stephan Orlovsky, May 24 2011

STATUS

approved

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Last modified October 20 18:19 EDT 2019. Contains 328269 sequences. (Running on oeis4.)