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A201021 Composite numbers whose multiplicative digital root is 7. 0
117, 171, 711, 1711, 7111, 11711, 17111, 71111, 111117, 111171, 111711, 117111, 171111, 711111, 1111117, 1111171, 1711111, 7111111, 11111711, 11117111, 11171111, 11711111, 17111111, 111111117, 111111171, 111111711, 111117111, 111171111, 111711111, 117111111, 171111111 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Also composite numbers whose product of digits is 7.

Complement of A107693 with respect to A034054. ~

LINKS

Table of n, a(n) for n=1..31.

FORMULA

Number 171 is in sequence because 1*7*1=7.

CROSSREFS

Cf. A107693 (primes whose multiplicative digital root is 7), A034054 (numbers whose multiplicative digital root is 7).

Sequence in context: A109023 A272388 A272389 * A187990 A112877 A064180

Adjacent sequences:  A201018 A201019 A201020 * A201022 A201023 A201024

KEYWORD

nonn,base

AUTHOR

Jaroslav Krizek, Nov 25 2011

STATUS

approved

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Last modified February 28 23:19 EST 2020. Contains 332353 sequences. (Running on oeis4.)