A037508 - OEIS

%I #11 Feb 13 2017 02:47:00

%S 1,9,63,442,3096,21672,151705,1061937,7433559,52034914,364244400,

%T 2549710800,17847975601,124935829209,874550804463,6121855631242,

%U 42852989418696,299970925930872,2099796481516105

%N Base 7 digits are, in order, the first n terms of the periodic sequence with initial period 1,2,0.

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (7,0,1,-7).

%H <a href="/index/Ar#7-automatic">Index entries for 7-automatic sequences</a>.

%F G.f.: x*(1+2*x) / ( (x-1)*(7*x-1)*(1+x+x^2) ). - _R. J. Mathar_, Apr 27 2015

%o (PARI) a(n)=([0,1,0,0; 0,0,1,0; 0,0,0,1; -7,1,0,7]^(n-1)*[1;9;63;442])[1,1] \\ _Charles R Greathouse IV_, Feb 13 2017

%Y Cf. A007093, A037511.

%K nonn,base,easy

%O 1,2

%A _Clark Kimberling_