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 A139249 #37 Apr 04 2025 23:42:49
%S A139249 6,36,66,96,126,156,186,216,246,276,306,336,366,396,426,456,486,516,
%T A139249 546,576,606,636,666,696,726,756,786,816,846,876,906,936,966,996,1026,
%U A139249 1056,1086,1116,1146,1176,1206,1236,1266,1296,1326,1356,1386,1416,1446,1476
%N A139249 a(n) = 30*n - 24.
%C A139249 Multiples of 6 with unit digit equal to 6.
%H A139249 Vincenzo Librandi, <a href="/A139249/b139249.txt">Table of n, a(n) for n = 1..2000</a>
%H A139249 William A. Stein, <a href="http://wstein.org/Tables/dimskg0n.gp">Dimensions of the spaces S_k(Gamma_0(N))</a>.
%H A139249 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F A139249 a(n) = a(n-1) + 30.
%F A139249 From _Elmo R. Oliveira_, Apr 04 2025: (Start)
%F A139249 G.f.: 6*x*(1+4*x)/(1-x)^2.
%F A139249 E.g.f.: 6*(exp(x)*(5*x - 4) + 4).
%F A139249 a(n) = 6*A016861(n-1).
%F A139249 a(n) = 2*a(n-1) - a(n-2) for n > 2. (End)
%t A139249 Range[6,7000,30] (* _Vladimir Joseph Stephan Orlovsky_, Jun 18 2011 *)
%t A139249 NestList[30+#&,6,50] (* or *) LinearRecurrence[{2,-1},{6,36},50] (* _Harvey P. Dale_, May 27 2018 *)
%o A139249 (Magma) [30*n - 24: n in [1..60]]; // _Vincenzo Librandi_, Jun 19 2011
%o A139249 (PARI) a(n)=30*n-24 \\ _Charles R Greathouse IV_, Aug 25 2014
%Y A139249 Subsequence of A034709, together with A017281, A017293, A139222, A139245, A017329, A139264, A139279 and A139280. - _Reinhard Zumkeller_, Jun 22 2008
%Y A139249 Cf. A016861.
%K A139249 easy,nonn
%O A139249 1,1
%A A139249 _Odimar Fabeny_, Jun 06 2008, Jun 07 2008
%E A139249 More terms from _Reinhard Zumkeller_, Jun 22 2008
%E A139249 Edited by _R. J. Mathar_, Jul 20 2008