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 A113802 #26 Nov 27 2024 07:26:21
%S A113802 2,12,16,26,30,40,44,54,58,68,72,82,86,96,100,110,114,124,128,138,142,
%T A113802 152,156,166,170,180,184,194,198,208,212,222,226,236,240,250,254,264,
%U A113802 268,278,282,292,296,306,310,320,324,334,338,348,352,362,366,376,380
%N A113802 Numbers that are congruent to {2, 12} mod 14.
%F A113802 a(n) = 14*n - a(n-1) - 14 (with a(1) = 2). - _Vincenzo Librandi_, Nov 13 2010
%F A113802 From _Wolfdieter Lang_, Dec 15 2011: (Start)
%F A113802 a(n) = 7*n-(7-3*(-1)^n)/2.
%F A113802 O.g.f.: 2*x*(1+5*x+x^2)/((1+x)*(1-x)^2).
%F A113802 See the contribution of _Bruno Berselli_ under A113801. (End)
%F A113802 Sum_{n>=1} (-1)^(n+1)/a(n) = cot(Pi/7)*Pi/14. - _Amiram Eldar_, Dec 30 2021
%F A113802 From _Amiram Eldar_, Nov 25 2024: (Start)
%F A113802 Product_{n>=1} (1 - (-1)^n/a(n)) = cosec(Pi/7)*sin(3*Pi/14).
%F A113802 Product_{n>=1} (1 + (-1)^n/a(n)) = cosec(Pi/7)*sin(Pi/14). (End)
%t A113802 Select[Range[400],MemberQ[{2,12},Mod[#,14]]&] (* _Harvey P. Dale_, Oct 30 2011 *)
%Y A113802 Second row A113807.
%Y A113802 Cf. A008589, A113801, A113803, A113804, A113805, A113806.
%K A113802 nonn,easy
%O A113802 1,1
%A A113802 _Giovanni Teofilatto_, Jan 22 2006