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 A048847 #18 Feb 16 2025 08:32:40
%S A048847 13,135791113151719,135791113151719212325272931,
%T A048847 135791113151719212325272931333537394143454749515355575961636567
%N A048847 Primes formed by concatenation of first k odd numbers.
%C A048847 The next term (a(5)) has 93 digits. - _Harvey P. Dale_, Mar 05 2013
%C A048847 a(6) has 9725 digits (see A066811(6) or A046036(6)). - _Michel Marcus_, Jan 31 2014
%D A048847 R. W. Stephan, Factors and Primes in Two Smarandache Sequences, Smarandache Notions Journal, second edition, Vol. 9, No. 1-2, 1998, 5-11.
%H A048847 M. Fleuren, <a href="http://www.gallup.unm.edu/~smarandache/SmConOdd.txt">Smarandache Concatenated Odds</a>.
%H A048847 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ConsecutiveNumberSequences.html">Consecutive Number Sequences</a>
%t A048847 Select[Table[FromDigits[Flatten[IntegerDigits/@Range[1,2n+1,2]]],{n,40}], PrimeQ] (* _Harvey P. Dale_, Mar 05 2013 *)
%Y A048847 Cf. A019519, A046036.
%K A048847 nonn,base
%O A048847 1,1
%A A048847 _N. J. A. Sloane_, Charles T. Le (charlestle(AT)yahoo.com)
%E A048847 Edited by _Charles R Greathouse IV_, Apr 23 2010