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 A007880 #9 Oct 01 2018 20:11:14
%S A007880 1,2,3,5,1,2,3,6,1,2,3,7,1,2,3,8,1,2,3,9,1,2,3,10,1,2,3,11,1,2,3,12,1,
%T A007880 2,3,13,1,2,3,14,1,2,3,15,1,2,3,16,1,2,3,5,1,2,3,6,1,2,3,7,1,2,3,8,1,
%U A007880 2,3,9,1,2,3,10,1,2,3,11,1,2,3,12,1,2,3,13,1,2,3,14,1,2,3,15,1,2,3,16
%N A007880 Westminster chimes at 15-minute intervals (1).
%t A007880 With[{c=Table[{{1,2,3},n},{n,5,16}]//Flatten},Join[c,c]] (* _Harvey P. Dale_, Oct 01 2018 *)
%K A007880 nonn
%O A007880 0,2
%A A007880 _Colin Mallows_