OFFSET
0,1
LINKS
Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,1).
FORMULA
a(n) = 1 + 6*[7|n], where [x|y] = 1 when x divides y, 0 otherwise.
a(n) = a(n-7).
Multiplicative with a(p^e, 7) = gcd(p^e, 7). - David W. Wilson, Jun 12 2005
From R. J. Mathar, Apr 04 2011: (Start)
Dirichlet g.f.: zeta(s)*(1 + 6/7^s).
G.f.: (-7 - x - x^2 - x^3 - x^4 - x^5 - x^6) / ((x-1)*(1 + x + x^2 + x^3 + x^4 + x^5 + x^6)). (End)
a(n) = 6*floor(((n-1) mod 7)/6) + 1. - Gary Detlefs, Dec 28 2011
MAPLE
MATHEMATICA
GCD[Range[0, 100], 7] (* or *) PadRight[{}, 120, {7, 1, 1, 1, 1, 1, 1}] (* Harvey P. Dale, Apr 26 2018 *)
CROSSREFS
KEYWORD
nonn,easy,mult
AUTHOR
STATUS
approved