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 A054264 #13 Aug 14 2024 15:40:40 %S A054264 4,6,8910,12,141516,18,202122,2425262728,30,3233343536,383940,42, %T A054264 444546,4849505152,5455565758,60,6263646566,686970,72,7475767778, %U A054264 808182,8485868788,90919293949596,9899100,102,104105106,108,110111112 %N A054264 Concatenation of composite numbers between the n-th prime and the following prime. %H A054264 Andrew Howroyd, <a href="/A054264/b054264.txt">Table of n, a(n) for n = 2..1000</a> %t A054264 FromDigits[Flatten[IntegerDigits/@(Range[#[[1]]+1,#[[2]]-1])]]&/@Partition[ Prime[Range[2,30]],2,1] (* _Harvey P. Dale_, Mar 04 2014 *) %o A054264 (PARI) a(n)=my(r=prime(n)+1); fromdigits(concat(vector(nextprime(r)-r, i, digits(r+i-1)))) \\ _Andrew Howroyd_, Aug 14 2024 %Y A054264 Cf. A046933, A054265, A054266, A054267, A054268. %K A054264 nonn,base,easy %O A054264 2,1 %A A054264 _Patrick De Geest_, Apr 15 2000 %E A054264 Offset changed and name edited by _Andrew Howroyd_, Aug 14 2024