login
A062667
Every divisor (except 1) contains the digit 3.
18
3, 13, 23, 31, 37, 39, 43, 53, 73, 83, 93, 103, 113, 131, 137, 139, 163, 173, 193, 223, 233, 239, 263, 283, 293, 307, 309, 311, 313, 317, 331, 337, 339, 347, 349, 353, 359, 367, 373, 379, 383, 389, 393, 397, 403, 431, 433, 439, 443, 463, 503, 523, 563, 593
OFFSET
1,1
LINKS
EXAMPLE
93 has divisors 1, 3, 31 and 93, all of which contain the digit 3.
MATHEMATICA
fQ[n_, dgt_] := Union[ MemberQ[#, dgt] & /@ IntegerDigits@ Rest@ Divisors@ n][[1]]; Select[ Range[2, 600], fQ[#, 3] &] (* Robert G. Wilson v, Jun 11 2014 *)
Select[Range[2, 600], AllTrue[Flatten[DigitCount[#, 10, 3]&/@Rest[Divisors[#]]], #>0&]&] (* Harvey P. Dale, Oct 04 2024 *)
KEYWORD
base,easy,nonn
AUTHOR
Erich Friedman, Jul 04 2001
EXTENSIONS
Offset corrected by Amiram Eldar, Nov 07 2019
STATUS
approved