A046513 Numbers with multiplicative persistence value 4.

77, 177, 268, 277, 286, 348, 355, 377, 378, 379, 384, 387, 397, 438, 446, 464, 467, 476, 477, 483, 489, 498, 535, 553, 557, 575, 628, 644, 647, 668, 674, 677, 678, 682, 686, 687, 699, 717, 727, 737, 738, 739, 746, 747, 755, 764, 767, 768, 771, 772, 773

Offset

1,1

Links

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

Eric Weisstein's World of Mathematics, Multiplicative Persistence

Example

737 -> [ 147 ][ 28 ][ 16 ][ 6 ] -> one digit in four steps.

Maple

mp:= proc(n) option remember;
    if n <= 9 then return 0 fi;
    1+procname(convert(convert(n, base, 10), `*`))
end proc:
select(mp=4, [$1..1000]); # Robert Israel, Feb 12 2019

Mathematica

pr4Q[n_] := Length[NestWhileList[Times @@ IntegerDigits[#] &, n, # > 9 &]] == 5; Select[Range[773], pr4Q] (* Jayanta Basu, Jun 26 2013 *)

Crossrefs

Cf. A003001, A014120, A046504.

Sequence in context: A308963 A075253 A217790 * A199994 A043518 A044409

Adjacent sequences: A046510 A046511 A046512 * A046514 A046515 A046516

Keyword

nonn,base

Author

Patrick De Geest, Sep 15 1998

Extensions

Offset corrected by Robert Israel, Feb 12 2019

Status

approved