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A243825
Numbers n such that every divisor greater than 1 contains the digit 0.
1
101, 103, 107, 109, 307, 401, 409, 503, 509, 601, 607, 701, 709, 809, 907, 1009, 1013, 1019, 1021, 1031, 1033, 1039, 1049, 1051, 1061, 1063, 1069, 1087, 1091, 1093, 1097, 1103, 1109, 1201, 1301, 1303, 1307, 1409, 1601, 1607, 1609, 1709, 1801, 1901, 1907, 2003, 2011, 2017, 2027, 2029
OFFSET
1,1
COMMENTS
This is an example of a composite number in the sequence which demonstrates that A056709 is a proper subsequence. - R. J. Mathar, Jun 13 2014
LINKS
EXAMPLE
The divisors of 10201 are {1, 101 & 10201}. Except for 1 each has a 0 in its decimal expansion.
MATHEMATICA
fQ[n_, dgt_] := Union[ MemberQ[#, dgt] & /@ IntegerDigits@ Rest@ Divisors@ n][[1]]; Select[ Range[2, 2030], fQ[#, 0] &]
PROG
(Magma) [m:m in [2..2100] | #[d:d in Divisors(m)|0 in Intseq(d)] eq #Divisors(m)-1]; // Marius A. Burtea, Nov 08 2019
CROSSREFS
Supersequence of A056709 (primes) and A243819 (composites).
Sequence in context: A085821 A183087 A056709 * A345728 A309488 A134809
KEYWORD
nonn,base,easy
AUTHOR
Barbara W. Waddell and Robert G. Wilson v, Jun 11 2014
STATUS
approved