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 A139608 #35 Apr 16 2024 10:26:17
%S A139608 8,36,64,92,120,148,176,204,232,260,288,316,344,372,400,428,456,484,
%T A139608 512,540,568,596,624,652,680,708,736,764,792,820,848,876,904,932,960,
%U A139608 988,1016,1044,1072,1100,1128,1156,1184,1212,1240,1268,1296,1324,1352,1380
%N A139608 a(n) = 28*n + 8.
%C A139608 Numbers of the 8th column of positive numbers in the square array of nonnegative and polygonal numbers A139600.
%D A139608 A. H. Beiler, Recreations in the Theory of Numbers, Dover, NY, 1964, p. 189. - From _N. J. A. Sloane_, Dec 01 2012
%H A139608 Vincenzo Librandi, <a href="/A139608/b139608.txt">Table of n, a(n) for n = 0..10000</a>
%H A139608 <a href="/index/Pol#polygonal_numbers">Index to sequences related to polygonal numbers</a>
%H A139608 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F A139608 a(n) = A057145(n+2,8).
%F A139608 a(n) = 2*a(n-1) - a(n-2); a(0)=8, a(1)=36. - _Harvey P. Dale_, Dec 14 2012
%F A139608 G.f.: 4*(2+5*x)/(x-1)^2. - _R. J. Mathar_, Jul 28 2016
%F A139608 From _Elmo R. Oliveira_, Apr 16 2024: (Start)
%F A139608 E.g.f.: 4*exp(x)*(2 + 7*x).
%F A139608 a(n) = 4*A017005(n) = A135628(n) + 8 = A316466(n+1) - A316466(n). (End)
%t A139608 Range[8, 7000, 28] (* _Vladimir Joseph Stephan Orlovsky_, Jul 13 2011 *)
%t A139608 LinearRecurrence[{2,-1},{8,36},50] (* or *) NestList[28+#&,8,50] (* _Harvey P. Dale_, Dec 14 2012 *)
%o A139608 (Magma) [4*(7*n + 2): n in [0..50]]; // _Vincenzo Librandi_, Jul 13 2011
%o A139608 (PARI) a(n)=28*n+8 \\ _Charles R Greathouse IV_, Oct 05 2011
%Y A139608 Cf. A017005, A057145, A135628, A139600, A316466.
%K A139608 easy,nonn
%O A139608 0,1
%A A139608 _Omar E. Pol_, Apr 27 2008