login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A028889 Numbers n such that iterated product of digits of n is a power of 2. 3
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

EXAMPLE

E.g. 38 -> 3*8 = 24 -> 2*4 = 8 is a power of 2.

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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 15 12:23 EDT 2019. Contains 328026 sequences. (Running on oeis4.)