login
A062675
Every divisor (except 1) contains the digit 7.
18
7, 17, 37, 47, 67, 71, 73, 79, 97, 107, 127, 137, 157, 167, 173, 179, 197, 227, 257, 271, 277, 307, 317, 337, 347, 367, 373, 379, 397, 457, 467, 479, 487, 497, 547, 557, 571, 577, 587, 607, 617, 647, 673, 677, 679, 701, 709, 719, 727, 733, 739, 743, 749, 751
OFFSET
1,1
LINKS
EXAMPLE
799 has divisors 17, 47 and 799, all of which contain the digit 7.
MATHEMATICA
fQ[n_, dgt_] := Union[ MemberQ[#, dgt] & /@ IntegerDigits@ Rest@ Divisors@ n][[1]]; Select[ Range[2, 760], fQ[#, 7] &] (* Robert G. Wilson v, Jun 11 2014 *)
PROG
(Magma) [k:k in [2..800]| forall{d:d in Set(Divisors(k)) diff {1}| 7 in Intseq(d)}]; // Marius A. Burtea, Nov 07 2019
KEYWORD
nonn,base,easy
AUTHOR
Erich Friedman, Jul 04 2001
STATUS
approved