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 A160751 #6 Feb 18 2019 04:09:36 %S A160751 6,61,613,6131 %N A160751 a(n) is the smallest n-digit prime formed by appending a digit to a(n-1); a(1)=6. %C A160751 There is no prime a(5) since all the integers from 61310 to 61319 are composite. %p A160751 A160751 := proc(n) option remember ; local d; if n =1 then 6; else for d from 1 to 9 by 2 do if isprime(10*procname(n-1)+d) then RETURN( 10*procname(n-1)+d ) ; fi; od: RETURN(-1) ; fi; end: seq(A160751(n),n=1..10) ; # _R. J. Mathar_, May 26 2009 %Y A160751 Cf. A000040, A160674. %K A160751 base,easy,fini,full,nonn %O A160751 1,1 %A A160751 _Juri-Stepan Gerasimov_, May 25 2009 %E A160751 Corrected by _R. J. Mathar_, May 26 2009