OFFSET
1,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (3, -2, -1, 1).
FORMULA
a(n) = L(-1)*(F(n+1)-1) + L(-2)*F(n) - L(-3)*n, F(n): Fibonacci (A000045), L(n): Lucas (A000032) with L(-n)=(-1)^n*L(n)
G.f.: x*(7-11*x)/((1-x-x^2)*(1-x)^2).
a(n) = Lucas(n-1) + 4*n + 1. - G. C. Greubel, Jun 01 2019
MATHEMATICA
Table[LucasL[n-1] +4*n+1, {n, 1, 40}] (* G. C. Greubel, Jun 01 2019 *)
PROG
(PARI) vector(40, n, fibonacci(n) + fibonacci(n-2) +4*n+1) \\ G. C. Greubel, Jun 01 2019
(Magma) [Lucas(n-1) + 4*n + 1 : n in [1..40]]; // G. C. Greubel, Jun 01 2019
(Sage) [lucas_number2(n-1, 1, -1) +4*n+1 for n in (1..40)] # G. C. Greubel, Jun 01 2019
(GAP) List([1..40], n-> Lucas(1, -1, n-1)[2] +4*n+1 ) # G. C. Greubel, Jun 01 2019
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
EXTENSIONS
Terms a(31) onward added by G. C. Greubel, Jun 01 2019
STATUS
approved