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 A159352 #13 Jul 07 2023 17:16:55 %S A159352 13,103,100003,1000003,100000000003,100000000000000003, %T A159352 1000000000000000003,1000000000000000000000000000000000000003, %U A159352 100000000000000000000000000000000000000000000000000000003 %N A159352 Primes of the form "1 [0]_n 3" - with zeros between 1 and 3. %H A159352 Dario Alejandro Alpern, <a href="https://www.alpertron.com.ar/ECM.HTM">Factorization using the Elliptic Curve Method</a> %H A159352 Makoto Kamada, <a href="https://stdkmd.net/nrr/1/10003.htm#prime">Prime numbers of the form 100...003</a>. %H A159352 <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>. %e A159352 1000000000000000000000000000000000000003 is a prime with 38 zeros between 1 and 3. %p A159352 select(isprime, [seq(10^k+3, k=1..998)]); # _Robert Israel_, Dec 28 2015 %o A159352 (Magma) [p: n in [1..100] | IsPrime(p) where p is 10^n+3 ]; // _Klaus Brockhaus_, Apr 12 2009 %Y A159352 Cf. A159031. %Y A159352 Cf. A049054 (numbers n such that 10^n + 3 is prime), A102006 (numbers n such that 10*10^n + 3 is prime), A011557 (powers of 10). %K A159352 base,nonn %O A159352 1,1 %A A159352 _Parthasarathy Nambi_, Apr 11 2009