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 A139113 #5 Dec 31 2015 18:30:59
%S A139113 11,21,32,43,55,68,713,821,934,1055,1189,12144,13233,14377,15610,
%T A139113 16987,171597,182584,194181,206765,2110946,2217711,2328657,2446368,
%U A139113 2575025,26121393,27196418,28317811,29514229,30832040,311346269,322178309
%N A139113 Concatenation of n and n-th Fibonacci number.
%t A139113 Table[FromDigits[Join[IntegerDigits[n],IntegerDigits[Fibonacci[n]]]],{n,40}] (* _Harvey P. Dale_, Dec 31 2015 *)
%Y A139113 Cf. A000027, A000045, A045532, A075110, A138821, A138822, A139114.
%K A139113 base,easy,nonn
%O A139113 1,1
%A A139113 _Omar E. Pol_, Apr 09 2008