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 A199995 #21 Apr 23 2022 12:36:48 %S A199995 679,688,697,796,868,886,976,1679,1688,1769,1796,1868,1886,1967,1976, %T A199995 2379,2388,2397,2468,2486,2648,2684,2688,2739,2793,2838,2846,2864, %U A199995 2868,2883,2886,2937,2973,3279,3288,3297,3367,3376,3448,3484,3488,3729,3736,3763 %N A199995 Composite numbers whose multiplicative persistence is 5. %C A199995 Complement of A046505 with respect to A046514. %H A199995 Harvey P. Dale, <a href="/A199995/b199995.txt">Table of n, a(n) for n = 1..1000</a> %e A199995 679 -> [ 378 ][ 168 ][ 48 ][ 32 ][ 6 ] -> one digit in five steps. %t A199995 persistence[n_] := Module[{cnt = 0, k = n}, While[k > 9, cnt++; k = Times @@ IntegerDigits[k]]; cnt]; Select[Range[4000], !PrimeQ[#] && persistence[#] == 5 &] (* _T. D. Noe_, Nov 23 2011 *) %t A199995 mp5Q[n_]:=CompositeQ[n]&&Length[NestWhileList[ Times@@IntegerDigits[ #]&,n,#>9&]] == 6; Select[Range[4000],mp5Q] (* _Harvey P. Dale_, Apr 23 2022 *) %Y A199995 Cf. A046505 (primes whose multiplicative persistence is 5). %K A199995 nonn,base %O A199995 1,1 %A A199995 _Jaroslav Krizek_, Nov 13 2011