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 A160954 #9 Aug 02 2024 11:05:37
%S A160954 18,181,1811,18119,181193,1811939
%N A160954 a(n+1) is the smallest prime formed by appending a single digit to a(n); a(1)=18.
%C A160954 There is no prime a(7) since 18119390 to 18119399 are all composite.
%e A160954 a(1)=18,
%e A160954 a(2)=181,
%e A160954 a(3)=1811,
%e A160954 a(4)=18119,
%e A160954 a(5)=181193,
%e A160954 a(6)=1811939. [Corrected by _Jon E. Schoenfield_, Feb 18 2019]
%p A160954 A160954 :=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 A160954 seq(A160954(n), n=1..10) ; _R. J. Mathar_, May 26 2009
%t A160954 spsd[n_]:=SelectFirst[Table[10n+d,{d,{1,3,7,9}}],PrimeQ]; NestList[spsd,18,5] (* _Harvey P. Dale_, Aug 02 2024 *)
%Y A160954 Cf. A000040, A160751, A160955.
%K A160954 nonn,base,easy,fini,full
%O A160954 1,1
%A A160954 _Juri-Stepan Gerasimov_, May 31 2009
%E A160954 Redundant part of the definition removed by _R. J. Mathar_, May 21 2010