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.
%I A334511 #22 Sep 11 2021 15:12:09 %S A334511 2,2,2,2,2,9,5,12,18,5,22,12,26,14,30,16,34,18,38,20,42,22,46,24,50, %T A334511 26,54,28,58,30,62,32,66,34,70,36,74,38,78,40,82,42,86,44,90,46,94,48, %U A334511 98,50,102,52,106,54,110,56,114,58,118,60,122,62,126,64,130 %N A334511 Eventual period of a single cell in rule 9 cellular automaton in a cyclic universe of width n. %C A334511 _Bradley Klee_ computed a(1)-a(10). %D A334511 Bradley Klee, Posting to Math Fun Mailing List, Apr 26 2020 %F A334511 Conjectures from _Colin Barker_, May 09 2020: (Start) %F A334511 G.f.: x*(2 + 2*x - 2*x^2 - 2*x^3 + 7*x^5 + 3*x^6 - 4*x^7 + 10*x^8 - 10*x^9 - 9*x^10 + 14*x^11 - 5*x^13) / ((1 - x)^2*(1 + x)^2). %F A334511 a(n) = 2*a(n-2) - a(n-4) for n>14. %F A334511 (End) %F A334511 Conjecture: a(n) = (3 - (-1)^n)*n/2 for n > 10. - _Stefano Spezia_, Sep 11 2021 %Y A334511 Cf. A180001, A334496, A334499-A334515. %K A334511 nonn %O A334511 1,1 %A A334511 _N. J. A. Sloane_, May 05 2020 %E A334511 More terms from _Jinyuan Wang_, May 09 2020