%I #18 Feb 15 2018 20:42:35
%S 1,2,4,8,14,25,44,76,132,228,393,678,1168,2012,3466,5969,10280,17704,
%T 30488,52504,90417,155706,268140,461760,795190,1369385,2358196,
%U 4061012,6993404,12043228,20739449,35715070,61504344,105915636,182395602,314100513
%N Number of binary strings of length n with no substrings equal to 0001 or 0011.
%H R. H. Hardin, <a href="/A164393/b164393.txt">Table of n, a(n) for n = 0..500</a>
%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (2,0,0,-2,1).
%F a(n) = 2*a(n-1) - 2*a(n-4) + a(n-5). - _Andrew Howroyd_, Feb 14 2018
%F G.f.: 1/((1 - x)*(1 - x - x^2 - x^3 + x^4)). - _R. J. Mathar_, Dec 01 2011
%t LinearRecurrence[{2,0,0,-2,1}, {1, 2, 4, 8, 14}, 50] (* _G. C. Greubel_, Sep 18 2017 *)
%o (PARI) Vec(1/((1 - x)*(1 - x - x^2 - x^3 + x^4)) + O(x^40)) \\ _G. C. Greubel_, Sep 18 2017
%K nonn
%O 0,2
%A _R. H. Hardin_, Aug 14 2009
%E a(0)-a(3) prepended by _Andrew Howroyd_, Feb 14 2018