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 A046504 #16 Feb 16 2025 08:32:39 %S A046504 277,379,397,467,557,647,677,727,739,773,787,877,887,937,1277,1483, %T A046504 1489,1553,1699,1747,1777,1783,1787,1867,1873,1877,1973,1999,2267, %U A046504 2347,2377,2399,2437,2467,2473,2477,2647,2683,2687,2689,2699,2797,2837,2861 %N A046504 Primes with multiplicative persistence value 4. %H A046504 Daniel Mondot, <a href="/A046504/b046504.txt">Table of n, a(n) for n = 1..10000</a> %H A046504 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MultiplicativePersistence.html">Multiplicative Persistence</a> %e A046504 277 -> [ 98 ][ 72 ][ 14 ][ 4 ] -> one digit in four steps. %t A046504 pmp4Q[n_]:=Length[NestWhileList[Times@@IntegerDigits[#]&,n,#>9&]]==5; Select[Prime[Range[500]],pmp4Q] (* _Harvey P. Dale_, Oct 10 2016 *) %Y A046504 Intersection of A000040 and A046513. %Y A046504 Cf. A046500. %K A046504 nonn,base %O A046504 1,1 %A A046504 _Patrick De Geest_, Sep 15 1998