A164400 - OEIS

%I #23 Apr 02 2019 17:06:28

%S 1,2,4,8,14,24,41,70,120,206,354,609,1048,1804,3106,5348,9209,15858,

%T 27308,47026,80982,139457,240156,413568,712198,1226464,2112073,

%U 3637166,6263504,10786278,18574874,31987489,55085136,94861220,163358970,281317836,484452889

%N Number of binary strings of length n with no substrings equal to 0001 or 1100.

%H Alois P. Heinz, <a href="/A164400/b164400.txt">Table of n, a(n) for n = 0..2000</a> (first 500 terms from R. H. Hardin)

%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (2,0,0,-2,1).

%F G.f.: (x^6+x^5-1)/((x-1)*(x^4-x^3-x^2-x+1)). - _R. J. Mathar_, Nov 28 2011

%t LinearRecurrence[{2, 0, 0, -2, 1}, {1, 2, 4, 8, 14, 24, 41}, 50] (* _G. C. Greubel_, Sep 18 2017; amended for offset 0 by _Georg Fischer_, Apr 02 2019 *)

%o (PARI) x='x+O('x^50); Vec((1-x^5-x^6)/((1-x)*(x^4-x^3-x^2-x+1))) \\ _G. C. Greubel_, Sep 18 2017; amended for offset 0 by _Georg Fischer_, Apr 02 2019

%K nonn,easy

%O 0,2

%A _R. H. Hardin_, Aug 14 2009

%E Edited by _Alois P. Heinz_, Oct 11 2017