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 A292314 #20 Oct 05 2017 13:26:25
%S A292314 18,126,168,216,468,918,1026,1140,1260,1518,1950,2106,2268,2790,3168,
%T A292314 3996,4218,5418,5676,5940,6210,6768,7056,7650,8268,8910,9240,9576,
%U A292314 9918,10266,10620,11346,11718,13668,14076,15336,15768,16650,17556,18018,18486,18960,20418,21420,22446
%N A292314 Numbers equal to the sum of three oblong numbers in arithmetic progression.
%C A292314 Subsequence of A028896.
%F A292314 a(n) = 3*A292316(n).
%e A292314 126 = 3*4 + 6*7 + 8*9 = 12 + 42 + 72, with 72 - 42 = 42 - 12 = 30;
%e A292314 468 = 8*9 + 12*13 + 15*16 = 72 + 156 + 240, with 240 - 156 = 156 - 72 = 84.
%t A292314 o[n_] := n(n+1); s[x_] := Reduce[ x+k == o[y] && x-k == o[z] && k>0 && z>0, {z, y, k}, Integers]; 3 Select[o@ Range@ 93, s[#] =!= False &] (* _Giovanni Resta_, Sep 18 2017 *)
%o A292314 (PARI) t=2; k=2; while(t<=10^4, i=k; e=0; v=t+i; while(i>2&&e==0, if(issquare(4*v+1), m=3*t; e=1; print1(m,", ")); i+=-2; v+=i); k+=2; t+=k)
%Y A292314 Cf. A292309, A292310, A292313, A292316.
%K A292314 nonn
%O A292314 1,1
%A A292314 _Antonio Roldán_, Sep 14 2017