%I #12 Jun 18 2017 02:24:18

%S 1,5,20,52,116,244,500,1012,2036,4084,8180,16372,32756,65524,131060,

%T 262132,524276,1048564,2097140,4194292,8388596,16777204,33554420,

%U 67108852,134217716,268435444,536870900,1073741812,2147483636

%N Sequence whose G.f is f such that: f(z)=8/(1-2*z)-12/(1-z)+z+5.

%C The Granvik array of A172119 is here written in "square": 1 :: 1 :: 1 :: 1 :: 1 :: 1 :: 1 :: 1 :: 1 :: 1 // 1 :: 2 :: 2 :: 2 :: 2 :: 2 :: 2 :: 2 :: 2 :: 2 // 1 :: 3 :: 4 :: 4 :: 4 :: 4 :: 4 :: 4 :: 4 :: 4 // 1 :: 4 :: 7 :: 8 :: 8 :: 8 :: 8 :: 8 :: 8 :: 8 // This sequence gives the third diagonal under the main diagonal.

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (3,-2)

%F a(n) = 8*2^n-12, n>=2. - R. J. Mathar, Apr 20 2011

%e From 1 + 5*z + 20*z^2 + 52*z^3 + 116*z^4 + 244*z^5 + 500*z^6 + O(z^7) we get a(6)=500.

%Y Cf. A172119, A173033.

%K easy,nonn

%O 0,2

%A _Richard Choulet_, Feb 07 2010