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 A154629 #24 Mar 04 2024 01:09:30 %S A154629 9,3,1,3,3,1,3,9,1,9,3,1,3,3,1,3,9,1,9,3,1,3,3,1,3,9,1,9,3,1,3,3,1,3, %T A154629 9,1,9,3,1,3,3,1,3,9,1,9,3,1,3,3,1,3,9,1,9,3,1,3,3,1,3,9,1,9,3,1,3,3, %U A154629 1,3,9,1,9,3,1,3,3,1,3,9,1,9,3,1,3,3 %N A154629 Period 9: repeat [9, 3, 1, 3, 3, 1, 3, 9, 1]. %C A154629 Greatest common divisor of (n+1)^2-1 and (n+1)^2+8. - _Bruno Berselli_, Mar 08 2017 %H A154629 Colin Barker, <a href="/A154629/b154629.txt">Table of n, a(n) for n = 0..1000</a> %H A154629 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,0,1). %F A154629 a(n) = A147674(n)/9. %F A154629 a(n) = A005563(n) / A144454(n+1) for n>0. %F A154629 From _Colin Barker_, Dec 21 2017: (Start) %F A154629 G.f.: (9 + 3*x + x^2 + 3*x^3 + 3*x^4 + x^5 + 3*x^6 + 9*x^7 + x^8) / ((1 - x)*(1 + x + x^2)*(1 + x^3 + x^6)). %F A154629 a(n) = a(n-9) for n>8. %F A154629 (End) %t A154629 With[{n=5}, PadLeft[{}, 9n, {9,3,1,3,3,1,3,9,1}]] (* _Harvey P. Dale_, Oct 22 2011 *) %o A154629 (PARI) Vec((9 + 3*x + x^2 + 3*x^3 + 3*x^4 + x^5 + 3*x^6 + 9*x^7 + x^8) / ((1 - x)*(1 + x + x^2)*(1 + x^3 + x^6)) + O(x^100)) \\ _Colin Barker_, Dec 21 2017 %Y A154629 Cf. A005563, A144454, A147674. %K A154629 nonn,easy %O A154629 0,1 %A A154629 _Paul Curtz_, Jan 13 2009