Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #10 May 30 2020 23:12:05
%S 1,2,4,8,15,26,42,74,132,236,421,747,1314,2318,4101,7263,12864,22773,
%T 40291,71272,126099,223144,394895,698823,1236609,2188185,3872000,
%U 6851631,12124307,21454602,37964931,67180507,118878510,210360283,372241362,658697067
%N Number of length n binary sequences with at most 3 of every 6 adjacent bits set.
%H Alois P. Heinz, <a href="/A133551/b133551.txt">Table of n, a(n) for n = 0..2000</a>
%H <a href="/index/Rec#order_20">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,0,0,1,3,0,-3,-1,0,0,-3,-1,3,0,0,0,1,0,-1).
%F G.f.: -(x^19 +x^18 -x^16 -x^15 -3*x^13 -2*x^12 +2*x^11 +4*x^10 +2*x^9 +x^8 +4*x^7 +4*x^6 -2*x^5 -3*x^4 -2*x^3 -x^2-x-1) / ((x-1) *(x+1) *(x^18 -3*x^12 +x^11 +x^9 +2*x^7 +3*x^6 +2*x^5 +x^3 +x -1)). - _Alois P. Heinz_, May 29 2020
%K nonn,easy
%O 0,2
%A _R. H. Hardin_, Dec 24 2007