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 A046505 #22 Feb 16 2025 08:32:39 %S A046505 769,967,1697,2777,3637,3673,4483,6197,6337,6373,6719,6733,6779,6791, %T A046505 6917,6971,6977,7559,7691,7727,8443,8681,8861,9677,9767,12379,12739, %U A046505 12973,13297,13367,13729,13763,14779,14797,14843,17239,17293,17497 %N A046505 Primes with multiplicative persistence value 5. %H A046505 Daniel Mondot, <a href="/A046505/b046505.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from Harvey P. Dale) %H A046505 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MultiplicativePersistence.html">Multiplicative Persistence</a> %e A046505 769 -> [ 378 ][ 168 ][ 48 ][ 32 ][ 6 ] -> one digit in five steps. %t A046505 mp5Q[n_]:=Length[NestWhileList[Times@@IntegerDigits[#]&,n,#>9&]]==6; Select[ Prime[Range[2100]],mp5Q] (* _Harvey P. Dale_, Dec 30 2019 *) %Y A046505 Intersection of A000040 and A046514. %Y A046505 Cf. A046500. %K A046505 nonn,base %O A046505 1,1 %A A046505 _Patrick De Geest_, Sep 15 1998