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 A385709 #16 Jul 19 2025 16:40:12
%S A385709 11,5,23,61,73,239,487,523,569,3461,1319,3373,8923,4937,12619,11489,
%T A385709 15569,32189,105173,135319,46619,56473,177127,234161,295861,471923,
%U A385709 664319,2366387,3183613,1092389,3513877,7702319,4632077,10666177,13977923,20825939,35821939
%N A385709 Least prime p such that the decimal expansion of p^2 contains exactly n distinct primes as substrings.
%H A385709 Zhining Yang, <a href="/A385709/b385709.txt">Table of n, a(n) for n = 1..66</a>
%e A385709 a(9) = 569 because 569^2 = 323761, which contains 9 distinct primes as substring:{2,3,7,23,37,61,761,3761,23761}, and no prime less than 569 has 9 solutions.
%t A385709 b = Table[{}, 9]; Do[d = IntegerDigits[p^2];
%t A385709 t = Union@Select[FromDigits /@ Flatten[Table[Partition[d, k, 1], {k, Length@d}], 1], PrimeQ]; c = Length@t;
%t A385709 If[b[[c]] == {}, b[[c]] = {p, p^2, t, c}], {p, Prime@Range@120}]; b // Grid
%Y A385709 Cf. A018834, A046837.
%K A385709 nonn,base
%O A385709 1,1
%A A385709 _Zhining Yang_, Jul 07 2025