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 A141721 #10 Dec 12 2023 08:25:29
%S A141721 2,7,8,5,8,7,2,3,0,3,2,7,8,5,8,7,2,3,0,3,2,7,8,5,8,7,2,3,0,3,2,7,8,5,
%T A141721 8,7,2,3,0,3,2,7,8,5,8,7,2,3,0,3,2,7,8,5,8,7,2,3,0,3,2,7,8,5,8,7,2,3,
%U A141721 0,3,2,7,8,5,8,7,2,3,0,3,2,7,8,5,8,7
%N A141721 A141631(n) mod 10.
%C A141721 Mentioned in A010716.
%C A141721 The sequence and its first differences (5, 1, -3, 3, -1, -5, 1, -3, 3, -1) are both periodic with period length 10.
%F A141721 a(n)=a(n-10), period 10 (2, 7, 8, 5, 8, 7, 2, 3, 0, 3).
%F A141721 Also: decimal expansion of the constant 309541367/1111111111. - _R. J. Mathar_, Oct 15 2008
%t A141721 Mod[#,10]&/@Table[3n^2-4n+3,{n,200}] (* _Harvey P. Dale_, Oct 28 2012 *)
%K A141721 nonn,less
%O A141721 1,1
%A A141721 _Paul Curtz_, Sep 12 2008
%E A141721 Edited by _R. J. Mathar_, Oct 15 2008
%E A141721 More terms from _Harvey P. Dale_, Oct 28 2012