cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A129722 Number of 0's in even position in all Fibonacci binary words of length n. A Fibonacci binary word is a binary word having no 00 subword.

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%I A129722 #34 Jan 02 2021 04:22:01
%S A129722 0,0,1,1,5,6,19,25,65,90,210,300,654,954,1985,2939,5911,8850,17345,
%T A129722 26195,50305,76500,144516,221016,411900,632916,1166209,1799125,
%U A129722 3283145,5082270,9197455,14279725,25655489,39935214,71293590,111228804,197452746,308681550
%N A129722 Number of 0's in even position in all Fibonacci binary words of length n. A Fibonacci binary word is a binary word having no 00 subword.
%H A129722 G. C. Greubel, <a href="/A129722/b129722.txt">Table of n, a(n) for n = 0..1000</a>
%H A129722 Moussa Benoumhani, <a href="http://www.emis.de/journals/JIS/VOL15/Benoumhani/benoumhani8.html">On the Modes of the Independence Polynomial of the Centipede</a>, Journal of Integer Sequences, Vol. 15 (2012), #12.5.1.
%H A129722 É. Czabarka, R. Flórez, and L. Junes, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL18/Florez/florez12.html">A Discrete Convolution on the Generalized Hosoya Triangle</a>, Journal of Integer Sequences, 18 (2015), #15.1.6.
%H A129722 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (1,4,-3,-4,1,1).
%F A129722 G.f.: z^2/( (1+z-z^2)*(1-z-z^2)^2 ).
%F A129722 a(2*n+1) = a(2*n) + a(2*n-1) (n>=1).
%F A129722 a(2*n+1) = A001871(n-1) (n>=1).
%F A129722 a(2*n) = A129720(2*n) = A001870(n-1).
%F A129722 a(n) = Sum_{ k=0..floor(n/2)} k*A129721(n,k).
%F A129722 a(n) = F(n)*(n+1)/5 + F(n+1)*(2*n - 5 + 5*(-1)^n)/20 where F = A000045. - _Greg Dresden_, Jan 01 2021
%e A129722 a(4)=5 because in 1110', 1111, 1101, 10'10', 10'11, 0110', 0111 and 0101 one has altogether five 0's in even position (marked by ').
%p A129722 G:=z^2/(1-z-z^2)^2/(1+z-z^2): Gser:=series(G,z=0,45): seq(coeff(Gser,z,n),n=0..42);
%t A129722 CoefficientList[Series[x^2/((1 + x - x^2)*(1 - x - x^2)^2), {x,0,50}], x] (* _G. C. Greubel_, Mar 09 2017 *)
%t A129722 LinearRecurrence[{1,4,-3,-4,1,1},{0,0,1,1,5,6},40] (* _Harvey P. Dale_, Apr 02 2018 *)
%o A129722 (PARI) x='x+O('x^50); concat([0,0], Vec(x^2/((1 + x - x^2)*(1 - x - x^2)^2))) \\ _G. C. Greubel_, Mar 09 2017
%Y A129722 Cf. A000045, A001870, A001871, A129719, A129720, A129721.
%K A129722 nonn
%O A129722 0,5
%A A129722 _Emeric Deutsch_, May 13 2007