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 A032608 #17 Feb 17 2024 10:29:43
%S A032608 14,25,36,47,58,69,710,811,912,1013,1114,1215,1316,1417,1518,1619,
%T A032608 1720,1821,1922,2023,2124,2225,2326,2427,2528,2629,2730,2831,2932,
%U A032608 3033,3134,3235,3336,3437,3538,3639,3740,3841,3942,4043,4144,4245
%N A032608 Concatenation of n and n + 3.
%t A032608 Table[FromDigits[Join[IntegerDigits[n],IntegerDigits[n+3]]],{n,50}] (* _Harvey P. Dale_, Jul 11 2011 *)
%t A032608 #[[1]]*10^IntegerLength[#[[2]]]+#[[2]]&/@Table[{n,n+3},{n,50}] (* _Harvey P. Dale_, May 21 2018 *)
%Y A032608 Cf. A001704, A020338.
%K A032608 nonn,base
%O A032608 1,1
%A A032608 _Patrick De Geest_, May 15 1998