OFFSET
1,2
LINKS
Colin Barker, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (7,0,1,-7).
FORMULA
a(n) = 7*a(n-1) + a(n-3) - 7*a(n-4).
a(n) = floor( (28/171)*7^n ). - Tani Akinari, Jul 16 2014
G.f.: x*(1+x) / ((1-x)*(1-7*x)*(1+x+x^2)). - Colin Barker, Dec 24 2015
EXAMPLE
The first six terms have base-7 representations 1, 11, 110, 1101, 11011, 110110.
PROG
(PARI) Vec(x*(1+x)/((1-x)*(1-7*x)*(1+x+x^2)) + O(x^30)) \\ Colin Barker, Dec 24 2015
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved