A046506 Primes with multiplicative persistence value 6.

8867, 23887, 27883, 28387, 28837, 32887, 34487, 34847, 38287, 38447, 43487, 44647, 46447, 47843, 48437, 48473, 49999, 72883, 74843, 78283, 78823, 82387, 82837, 84347, 84437, 87443, 88237, 88327, 94999, 118687, 123887, 126487, 128467

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Multiplicative Persistence

Example

8867 -> [ 2688 ][ 768 ][ 336 ][ 54 ][ 20 ][ 0 ] -> one digit in six steps.

Maple

filter:= proc(n) local L, i;
  L:= convert(convert(n, base, 10), `*`); if L < 10 then return false fi;
  for i from 2 to 5 do
     L:= convert(convert(L, base, 10), `*`); if L < 10 then return false fi
    od;
  L:= convert(convert(L, base, 10), `*`); evalb(L < 10)
end proc:
count:= 0: Res:= NULL;
p:= 11:
while count < 100 do
  p:= nextprime(p);
  if filter(p) then count:= count+1; Res:= Res, p fi
od:
Res; # Robert Israel, Jun 06 2018

Crossrefs

Cf. A046500, A046515.

Sequence in context: A236031 A071564 A031625 * A116242 A116275 A116295

Adjacent sequences: A046503 A046504 A046505 * A046507 A046508 A046509

Keyword

nonn,base

Author

Patrick De Geest, Sep 15 1998

Extensions

Offset corrected by Robert Israel, Jun 06 2018

Status

approved