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 A134795 #4 Sep 06 2015 16:23:23
%S A134795 2,26,2612,261220,26122030,2612203042,261220304256,26122030425672,
%T A134795 2612203042567290,2612203042567290110,2612203042567290110132,
%U A134795 2612203042567290110132156,2612203042567290110132156182
%N A134795 Concatenation of first n positive oblong numbers.
%C A134795 Oblong numbers are also called promic, pronic or heteromecic (numbers).
%t A134795 Module[{nn=20,c},c=2*Accumulate[Range[nn]];Table[FromDigits[ Flatten[ IntegerDigits/@ Take[c,n]]],{n,nn}]] (* _Harvey P. Dale_, Sep 06 2015 *)
%Y A134795 Cf. A007908, A132932. Oblong numbers: A002378.
%K A134795 base,easy,nonn
%O A134795 1,1
%A A134795 _Omar E. Pol_, Nov 26 2007