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 A049637 #18 Apr 21 2019 10:51:48
%S A049637 2,6,8,10,12,15,16,19,21,23,25,28,29,32,34,36,38,41,42,45,47,49,51,54,
%T A049637 55,58,60,62,64,67,68,71,73,75,77,80,81,84,86,88,90,93,94,97,99,101,
%U A049637 103,106,107,110,112,114,116,119,120,123,125,127,129,132,133,136,138,140,142,145,146
%N A049637 Congruent to 2, 3, 6, 8, 10 or 12 mod 13, but not equal to 3.
%C A049637 a(n) = T(n, 3), array T as in A049627.
%H A049637 G. C. Greubel, <a href="/A049637/b049637.txt">Table of n, a(n) for n = 0..1000</a>
%H A049637 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (0,1,1,0,-1).
%F A049637 G.f.: 2 - x*(-6-8*x-4*x^2+2*x^3+3*x^4) / ( (1+x)*(1+x+x^2)*(x-1)^2 ). - _R. J. Mathar_, Oct 26 2015
%t A049637 CoefficientList[Series[2 - x*(-6 - 8*x - 4*x^2 + 2*x^3 + 3*x^4)/((1 + x)*(1 + x + x^2)*(x - 1)^2), {x, 0, 50}], x] (* _G. C. Greubel_, Dec 15 2017 *)
%t A049637 LinearRecurrence[{0,1,1,0,-1},{2,6,8,10,12,15},70] (* _Harvey P. Dale_, Apr 21 2019 *)
%o A049637 (PARI) x='x+O('x^30); Vec(2 - x*(-6 - 8*x - 4*x^2 + 2*x^3 + 3*x^4)/((1 + x)*(1 + x + x^2)*(x - 1)^2)) \\ _G. C. Greubel_, Dec 15 2017
%K A049637 nonn,easy
%O A049637 0,1
%A A049637 _Clark Kimberling_
%E A049637 Terms a(38) onward added by _G. C. Greubel_, Dec 15 2017