A062677 Numbers with property that every divisor (except 1) contains the digit 8.

83, 89, 181, 281, 283, 383, 389, 487, 587, 683, 787, 809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883, 887, 983, 1087, 1181, 1187, 1283, 1289, 1381, 1481, 1483, 1487, 1489, 1583, 1783, 1787, 1789, 1801, 1811, 1823, 1831, 1847, 1861

Offset

1,1

Comments

Subsequence of A011538, numbers with an 8. - Michel Marcus, Nov 21 2015

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

7387 has divisors 83, 89 and 7387, all of which contain the digit 8.

Maple

isA062677 := proc(n)
    if n = 1 then
        return false;
    end if;
    for d in numtheory[divisors](n) minus {1} do
        convert(convert(d, base, 10), set) ;
        if  not 8 in % then
            return false;
        end if;
    end do:
    true ;
end proc:
for n from 1 to 2000 do
    if isA062677(n) then
        printf("%d, ", n) ;
    end if;
end do: # R. J. Mathar, Mar 27 2017

Mathematica

fQ[n_, dgt_] := Union[ MemberQ[#, dgt] & /@ IntegerDigits@ Rest@ Divisors@ n][[1]]; Select[ Range[2, 1900], fQ[#, 8] &] (* Robert G. Wilson v, Jun 11 2014 *)

Crossrefs

Cf. A062653, A062664, A062667, A062668, A062669, A062670, A062671, A062672, A062673, A062674, A062675, A062676, A062678, A062679, A062680.

Sequence in context: A130286 A372042 A226380 * A284292 A045714 A090156

Adjacent sequences: A062674 A062675 A062676 * A062678 A062679 A062680

Keyword

base,easy,nonn

Author

Erich Friedman, Jul 04 2001

Status

approved