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A049677
a(n) = (F(8*n+6) + F(8*n+1))/3, where F = A000045 (the Fibonacci sequence).
1
3, 137, 6436, 302355, 14204249, 667297348, 31348771107, 1472724944681, 69186723628900, 3250303285613619, 152695067700211193, 7173417878624312452, 336997945227642474051, 15831730007820571967945, 743754312422339240019364, 34940620953842123708942163, 1641465430518157475080262297
OFFSET
0,1
FORMULA
From Philippe Deléham, Nov 18 2008: (Start)
a(n) = 47*a(n-1) - a(n-2), a(0)=3, a(1)=137.
G.f.: (3-4*x)/(1-47*x+x^2). (End)
EXAMPLE
a(2) = (F(8 * 2 + 6) + F(8 * 2 + 1)) / 3 = (F(22) + F(17)) / 3 = (17711 + 1597) / 3 = 19308 / 3 = 6436. - Indranil Ghosh, Feb 05 2017
MATHEMATICA
Table[(Fibonacci[8*n+6] + Fibonacci[8*n+1])/3, {n, 0, 30}] (* or *) LinearRecurrence[{47, -1}, {3, 137}, 30] (* G. C. Greubel, Dec 02 2017 *)
PROG
(PARI) a(n) = (fibonacci(8*n+6)+fibonacci(8*n+1))/3; \\ Michel Marcus, Feb 05 2017
(Magma) [(Fibonacci(8*n+6) + Fibonacci(8*n+1))/3: n in [0..30]]; // G. C. Greubel, Dec 02 2017
CROSSREFS
KEYWORD
nonn,easy
STATUS
approved