OFFSET
1,1
COMMENTS
All numbers in this sequence are:
congruent to 9 mod 10 (iff n is odd),
congruent to 1 mod 10 (iff n is even).
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..795
Index entries for linear recurrences with constant coefficients, signature (13,104,-260,-260,104,13,-1).
FORMULA
From R. J. Mathar, Oct 22 2010: (Start)
a(n) = +13*a(n-1) +104*a(n-2) -260*a(n-3) -260*a(n-4) +104*a(n-5) +13*a(n-6) -a(n-7).
G.f.: -x*(-29+96*x+550*x^2-290*x^3-200*x^4+16*x^5+x^6) / ( (1+x)*(x^2-3*x+1)*(x^2-18*x+1)*(x^2+7*x+1) ).
MATHEMATICA
Table[LucasL[7*n]/LucasL[n], {n, 1, 50}]
PROG
(PARI) {lucas(n) = fibonacci(n+1) + fibonacci(n-1)};
for(n=0, 30, print1( lucas(7*n)/lucas(n), ", ")) \\ G. C. Greubel, Dec 21 2017
(Magma) [Lucas(7*n)/Lucas(n): n in [0..30]]; // G. C. Greubel, Dec 21 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Dec 20 2008
STATUS
approved