A180597 - OEIS

%I #19 Sep 25 2022 10:28:47

%S 0,7,5,3,1,8,6,4,2,9,7,5,3,1,8,6,4,2,9,7,5,3,1,8,6,4,2,9,7,5,3,1,8,6,

%T 4,2,9,7,5,3,1,8,6,4,2,9,7,5,3,1,8,6,4,2,9,7,5,3,1,8,6,4,2,9,7,5,3,1,

%U 8,6,4,2,9,7,5,3,1,8,6,4,2,9,7,5,3,1,8,6,4,2,9,7,5,3,1,8,6,4,2,9,7,5,3,1,8

%N Digital root of 7n.

%C Period of 9. - _Robert G. Wilson v_, Sep 20 2010

%H <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,0,1).

%F G.f.: x*(7 + 5*x + 3*x^2 + x^3 + 8*x^4 + 6*x^5 + 4*x^6 + 2*x^7 + 9*x^8)/(1 - x^9). - _Stefano Spezia_, Apr 21 2022

%F a(n) = A010888(A008589(n)). - _Michel Marcus_, Apr 21 2022

%t f[n_] := Mod[7 n - 1, 9] + 1; f[0] = 0; Array[f, 105, 0] (* _Robert G. Wilson v_, Sep 20 2010 *)

%o (PARI) a(n)=7*n%9 \\ _Charles R Greathouse IV_, Aug 22 2014

%Y Cf. A010888, A008589.

%Y Cf. A180592, A180594, A180595, A180596, A180592, A180593, A180594, A180595, A180596, A180598, A180599.

%Y Column k = 7 in A353109.

%K easy,nonn,base

%O 0,2

%A _Odimar Fabeny_, Sep 10 2010

%E More terms from _Robert G. Wilson v_, Sep 20 2010