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 A053067 #41 Jul 02 2025 16:01:59
%S A053067 1,23,456,78910,1112131415,161718192021,22232425262728,
%T A053067 2930313233343536,373839404142434445,46474849505152535455,
%U A053067 5657585960616263646566,676869707172737475767778,79808182838485868788899091,9293949596979899100101102103104105,106107108109110111112113114115116117118119120
%N A053067 a(n) is the concatenation of next n numbers (omit leading 0's).
%C A053067 Concatenation of the integers from A000124(n-1) up to and including A000217(n). - _R. J. Mathar_, Aug 30 2013
%C A053067 The second term is a prime. When is the next prime, if there is another? - _N. J. A. Sloane_, Dec 16 2016
%D A053067 Felice Russo, A set of new Smarandache functions, sequences and conjectures in number theory, American Research Press 2000.
%H A053067 Michael S. Branicky, <a href="/A053067/b053067.txt">Table of n, a(n) for n = 1..200</a>
%t A053067 Table[FromDigits[Flatten[IntegerDigits/@Range[(n(n-1))/2+1,(n(n+1))/2]]],{n,20}] (* _Harvey P. Dale_, Jan 23 2016 *)
%o A053067 (PARI) a(n) = my(s = ""); for (i=n*(n-1)/2 + 1, n*(n+1)/2, s = concat(s, Str(i));); eval(s); \\ _Michel Marcus_, Aug 11 2017
%o A053067 (Python)
%o A053067 def a(n): return int("".join(map(str, range((n-1)*n//2+1, n*(n+1)//2+1))))
%o A053067 print([a(n) for n in range(1, 16)]) # _Michael S. Branicky_, Jan 23 2021
%Y A053067 A subsequence of A035333. For primes in latter, see A052087.
%Y A053067 See A279610 for a variant.
%K A053067 easy,base,nonn
%O A053067 1,2
%A A053067 _Felice Russo_, Feb 25 2000
%E A053067 More terms from _James Sellers_, Feb 28 2000
%E A053067 More terms from _Michel Marcus_, Aug 11 2017