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A201015 Composite numbers whose product of digits is 2. 0
12, 21, 112, 121, 1112, 1121, 1211, 11112, 11121, 11211, 12111, 21111, 111112, 121111, 211111, 1111112, 1111121, 1112111, 1121111, 1211111, 2111111, 11111112, 11111121, 11111211, 11112111, 11121111, 11211111, 12111111, 21111111, 111111112, 111111121, 111111211 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Complement of A107612 with respect to  A199986. Subsequence of A199981 (composite numbers whose multiplicative digital root is 2).

LINKS

Table of n, a(n) for n=1..32.

EXAMPLE

Number 121 is in sequence because 1*2*1=2.

MATHEMATICA

Sort[Select[FromDigits/@Flatten[Table[Permutations[Join[{2}, PadRight[ {}, n, 1]]], {n, 10}], 1], CompositeQ]] (* Harvey P. Dale, Oct 23 2015 *)

CROSSREFS

Cf. A107612 (primes whose product of digits is 2), A199986 (numbers whose product of digits is 2).

Sequence in context: A039402 A043225 A111066 * A044005 A321771 A225864

Adjacent sequences:  A201012 A201013 A201014 * A201016 A201017 A201018

KEYWORD

nonn,base

AUTHOR

Jaroslav Krizek, Nov 25 2011

STATUS

approved

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Last modified February 26 08:33 EST 2020. Contains 332277 sequences. (Running on oeis4.)