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A206159 Numbers needing at most two digits to write all positive divisors in decimal representation. 4
1, 11, 13, 17, 19, 31, 41, 61, 71, 101, 113, 121, 131, 151, 181, 191, 199, 211, 311, 313, 331, 661, 811, 881, 911, 919, 991, 1111, 1117, 1151, 1171, 1181, 1511, 1777, 1811, 1999, 2111, 2221, 3313, 3331, 4111, 4441, 6661, 7177, 7717, 8111, 9199, 10111, 11113 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A095048(a(n)) <= 2; apparently 1, 121 and 1111 are the only nonprime terms.

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..476

PROG

(Haskell)

a206159 n = a206159_list !! (n-1)

a206159_list = filter ((<= 2) . a095048) [1..]

CROSSREFS

Cf. A027750, A031955, A011531, A106101, A004022, A062634.

Sequence in context: A062634 A239058 A208270 * A106101 A032590 A181576

Adjacent sequences:  A206156 A206157 A206158 * A206160 A206161 A206162

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller, Feb 05 2012

STATUS

approved

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Last modified October 19 03:08 EDT 2019. Contains 328211 sequences. (Running on oeis4.)