A028889 Numbers whose iterated product of digits is a power of 2.

1, 2, 4, 8, 11, 12, 14, 18, 21, 22, 24, 26, 27, 29, 34, 36, 37, 38, 39, 41, 42, 43, 46, 49, 62, 63, 64, 66, 67, 72, 73, 76, 77, 79, 81, 83, 88, 89, 92, 93, 94, 97, 98, 99, 111, 112, 114, 118, 121, 122, 124, 126, 127, 129, 134, 136, 137, 138, 139, 141, 142, 143, 146, 149, 162, 163, 164, 166, 167

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

38 -> 3*8 = 24 -> 2*4 = 8 = 2^3.

Mathematica

p2Q[n_]:=IntegerQ[Log[2, NestWhile[Times@@IntegerDigits[#]&, n, #>9&]]]; Select[ Range[200], p2Q] (* Harvey P. Dale, Sep 19 2019 *)

Crossrefs

Cf. A031347, A028846, A028836.

Sequence in context: A116636 A256980 A014425 * A235700 A174781 A028846

Adjacent sequences: A028886 A028887 A028888 * A028890 A028891 A028892

Keyword

nonn,base

Author

N. J. A. Sloane

Extensions

Extended (and corrected) by Scott Lindhurst (ScottL(AT)alumni.princeton.edu)

Status

approved