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 A047337 #30 Sep 08 2022 08:44:57
%S A047337 0,1,2,3,4,7,8,9,10,11,14,15,16,17,18,21,22,23,24,25,28,29,30,31,32,
%T A047337 35,36,37,38,39,42,43,44,45,46,49,50,51,52,53,56,57,58,59,60,63,64,65,
%U A047337 66,67,70,71,72,73,74,77,78
%N A047337 Numbers that are congruent to {0, 1, 2, 3, 4} mod 7.
%H A047337 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,0,1,-1).
%F A047337 a(n) = 7*floor((n-1)/5) + ((n-1) mod 5). - _Gary Detlefs_, Mar 09 2010
%F A047337 G.f.: x^2*(1 + x + x^2 + x^3 + 3*x^4) / ( (1 + x + x^2 + x^3 + x^4)*(x-1)^2 ). - _R. J. Mathar_, Dec 04 2011
%F A047337 a(n) = floor((7/6)*floor(6*(n-1)/5)). - _Bruno Berselli_, May 03 2016
%t A047337 DeleteCases[Range[0,80],_?(Mod[#,7]>4&)] (* _Harvey P. Dale_, Aug 21 2013 *)
%o A047337 (Magma) [n: n in [0..150] | n mod 7 in [0..4]]; // _Vincenzo Librandi_, May 04 2016
%K A047337 nonn,easy
%O A047337 1,3
%A A047337 _N. J. A. Sloane_