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A036303 Composite numbers n such that digits of prime factors of n are either 1 or 3. 3
9, 27, 33, 39, 81, 93, 99, 117, 121, 143, 169, 243, 279, 297, 339, 341, 351, 363, 393, 403, 429, 507, 729, 837, 891, 933, 939, 961, 993, 1017, 1023, 1053, 1089, 1179, 1209, 1243, 1287, 1331, 1441, 1469, 1521, 1573, 1703, 1859, 2187, 2197, 2511, 2673, 2799 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All terms are a product of at least two terms of A020451. - David A. Corneth, Oct 09 2020

LINKS

David A. Corneth, Table of n, a(n) for n = 1..10000 (first 1000 terms from Alois P. Heinz)

Index entries for sequences related to prime factors

EXAMPLE

The composite 117 = 3^2 * 13 is in the sequence as the digits of the prime factors are either 1 or 3. - David A. Corneth, Oct 17 2020

CROSSREFS

Cf. A003597, A036302-A036325.

Sequence in context: A255343 A108107 A216168 * A325299 A116455 A103753

Adjacent sequences:  A036300 A036301 A036302 * A036304 A036305 A036306

KEYWORD

nonn,easy,base

AUTHOR

Patrick De Geest, Dec 15 1998

STATUS

approved

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Last modified November 25 11:32 EST 2020. Contains 338623 sequences. (Running on oeis4.)