A164416 - OEIS

%I #12 Jul 25 2021 13:55:27

%S 13,23,40,69,120,208,361,626,1086,1884,3268,5669,9834,17059,29592,

%T 51333,89047,154469,267956,464821,806321,1398718,2426344,4208958,

%U 7301243,12665403,21970565,38112149,66112815,114685328,198943646,345105821

%N Number of binary strings of length n with no substrings equal to 0000 0001 or 1111

%H R. H. Hardin, <a href="/A164416/b164416.txt">Table of n, a(n) for n=4..500</a>

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

%F G.f.: -x^4*(13+23*x+27*x^2+20*x^3+8*x^4) / ( -1+x^2+2*x^3+2*x^4+x^5 ). - _R. J. Mathar_, Nov 30 2011

%K nonn

%O 4,1

%A _R. H. Hardin_ Aug 14 2009