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 A160955 #6 Feb 18 2019 16:56:02 %S A160955 18,181,1811,18119,181199,1811993 %N A160955 a(n+1) is the largest prime formed by appending a single digit to a(n); a(1)=18. %C A160955 There is no prime a(7) since 18119930 to 18119939 are all composite. %e A160955 a(1)=18, %e A160955 a(2)=181, %e A160955 a(3)=1811, %e A160955 a(4)=18119, %e A160955 a(5)=181199, %e A160955 a(6)=1811993. [Corrected by _Jon E. Schoenfield_, Feb 18 2019] %p A160955 A160955 :=proc(n) option remember ; local d; if n =1 then 18; else for d from 1 to 9 by 2 do if isprime(10*prochame n+d) then RETURN(10*procnam n+d 0 ; fi; end: %p A160955 seq(A160955(n), n=1..10) ; # _R. J. Mathar_, May 26 2009 %Y A160955 Cf. A000040, A160751, A160954. %K A160955 nonn,base,easy,fini,full %O A160955 1,1 %A A160955 _Juri-Stepan Gerasimov_, May 31 2009 %E A160955 Redundant part of the definition removed by _R. J. Mathar_, May 21 2010