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A284295 Numbers n such that product of digits of n is a power of 9. 5
1, 9, 11, 19, 33, 91, 99, 111, 119, 133, 191, 199, 313, 331, 339, 393, 911, 919, 933, 991, 999, 1111, 1119, 1133, 1191, 1199, 1313, 1331, 1339, 1393, 1911, 1919, 1933, 1991, 1999, 3113, 3131, 3139, 3193, 3311, 3319, 3333, 3391, 3399, 3913, 3931, 3939, 3993 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Supersequence of A284294.

LINKS

Table of n, a(n) for n=1..48.

EXAMPLE

1111 is in the sequence because 1*1*1*1 = 1 = 9^0.

MATHEMATICA

FromDigits /@ Select[Join @@ Map[Tuples[{1, 3, 9}, #] &, Range@ 4], IntegerQ@ Log[9, Times @@ #] &] (* Michael De Vlieger, Mar 25 2017 *)

PROG

(MAGMA) Set(Sort([n: n in [1..10000], k in [0..20] | &*Intseq(n) eq 9^k]))

CROSSREFS

Cf. Numbers n such that product of digits of n is a power of k for k = 0 - 9: A284375 (k = 0), A002275 (k = 1), A028846 (k = 2), A174813 (k = 3), A284323 (k = 4), A276037 (k = 5), A276038 (k = 6), A276039 (k = 7), A284324 (k = 8), this sequence (k = 9).

Sequence in context: A299971 A090771 A329279 * A284294 A195572 A046259

Adjacent sequences:  A284292 A284293 A284294 * A284296 A284297 A284298

KEYWORD

nonn,base

AUTHOR

Jaroslav Krizek, Mar 25 2017

STATUS

approved

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Last modified January 22 14:02 EST 2020. Contains 331149 sequences. (Running on oeis4.)