%I #18 Sep 08 2022 08:45:03

%S 7,17,37,47,67,71,73,79,97,107,127,137,157,167,173,179,197,227,257,

%T 271,277,307,317,337,347,367,373,379,397,457,467,479,487,497,547,557,

%U 571,577,587,607,617,647,673,677,679,701,709,719,727,733,739,743,749,751

%N Every divisor (except 1) contains the digit 7.

%H Amiram Eldar, <a href="/A062675/b062675.txt">Table of n, a(n) for n = 1..10000</a>

%e 799 has divisors 17, 47 and 799, all of which contain the digit 7.

%t fQ[n_, dgt_] := Union[ MemberQ[#, dgt] & /@ IntegerDigits@ Rest@ Divisors@ n][[1]]; Select[ Range[2, 760], fQ[#, 7] &] (* _Robert G. Wilson v_, Jun 11 2014 *)

%o (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

%Y Cf. A062653, A062664, A062667, A062668, A062669, A062670, A062671, A062672, A062673, A062674, A062676, A062677, A062678, A062679, A062680.

%K nonn,base,easy

%O 1,1

%A _Erich Friedman_, Jul 04 2001