A046508 Primes with multiplicative persistence value 8.

2678789, 2687879, 2687897, 2688797, 2688977, 2689877, 2697887, 2768789, 2768897, 2769887, 2778689, 2786789, 2787689, 2788769, 2798687, 2798867, 2868779, 2868977, 2876789, 2876879, 2878679, 2878697, 2878769, 2879687

Offset: 1

Author

Patrick De Geest, Sep 15 1998

Keywords

• nonn
• base

Examples

			2678789 -> [ 338688 ][ 27648 ][ 2688 ][ 768 ][ 336 ][ 54 ][ 20 ][ 0 ] -> one digit in eight steps.
		

Links

• Daniel Mondot, Table of n, a(n) for n = 1..10000 (terms 1..9001 from Harvey P. Dale)
• Eric Weisstein's World of Mathematics, Multiplicative Persistence

Crossrefs

Intersection of A000040 and A046517.

Cf. A046500.

Programs

Mathematica

mp8Q[n_]:=Length[NestWhileList[Times@@IntegerDigits[#]&,n,#>9&]]==9; Select[ Prime[ Range[210000]],mp8Q] (* Harvey P. Dale, Mar 30 2019 *)