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 A147554 #24 Sep 11 2024 12:18:36 %S A147554 3,13,37,9901,333667,99990001,999999000001,9999999900000001, %T A147554 13168164561429877,130654897808007778425046117 %N A147554 Primes p such that p^2 divides p.p.p where dot "." means concatenation. %C A147554 Primes p dividing 10^(2*d)+10^d+1 where d=ceiling(log(p)/log(10)) is the number of decimal digits in p. - _Max Alekseyev_ %C A147554 There is no prime p such that p^2 divides p.p. %C A147554 All primes of the forms 10^(2m) - 10^m + 1 or (1/3)*(10^(2m) + 10^m + 1) are in the sequence. %C A147554 Primes in A243162. - _Hans Havermann_, May 31 2014 %C A147554 a(11) > 10^158. - _Max Alekseyev_, Sep 11 2024 %Y A147554 Cf. A147553, A243162. %K A147554 nonn,base,more %O A147554 1,1 %A A147554 _Farideh Firoozbakht_, Dec 26 2008