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A216478 a(n) is the least multiple of n which uses only digits 1 and 2. a(n) = -1 if no such multiple exists. 0
1, 2, 12, 12, -1, 12, 21, 112, 12222, -1, 11, 12, 221, 112, -1, 112, 221, 12222, 1121, -1, 21, 22, 12121, 2112, -1, 1222, 21222, 112, 12122, -1, 11222, 2112, 1122, 1122, -1, 22212, 111, 12122, 111111, -1, 11111, 12222, 12212, 2112, -1, 122222, 1222, 2112, 11221, -1, 1122, 21112, 212, 21222, -1, 112, 212211, 12122, 1121 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..59.

CROSSREFS

Cf. A004290, A079339, A181060, A181061.

Sequence in context: A280015 A245281 A308215 * A181060 A171446 A068515

Adjacent sequences:  A216475 A216476 A216477 * A216479 A216480 A216481

KEYWORD

sign,base

AUTHOR

V. Raman, Sep 07 2012

STATUS

approved

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Last modified October 27 05:51 EDT 2020. Contains 338035 sequences. (Running on oeis4.)