OFFSET
1,1
COMMENTS
FORMULA
a(n) ~ n.
EXAMPLE
18 is in sequence because the list of divisors of 18: (1, 2, 3, 6, 9, 18) contains digit 8.
MAPLE
select(t -> has(map(convert, numtheory:-divisors(t), base, 10), 8), [$1..200]); # Robert Israel, May 14 2015
MATHEMATICA
Select[Range@108, Part[Plus @@ DigitCount@ Divisors@ #, 8] > 0 &]
Select[Range[200], SequenceCount[Flatten[IntegerDigits/@Divisors[#]], {8}]> 0&] (* Harvey P. Dale, Aug 02 2021 *)
PROG
(Magma) [n: n in [1..1000] | [8] subset Setseq(Set(Sort(&cat[Intseq(d): d in Divisors(n)])))]
(PARI) is(n)=fordiv(n, d, if(setsearch(Set(digits(d)), 8), return(1))); 0
(Python)
from itertools import count, islice
from sympy import divisors
def A257225_gen(): return filter(lambda n:any('8' in str(d) for d in divisors(n, generator=True)), count(1))
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Jaroslav Krizek, May 07 2015
EXTENSIONS
Mathematica and PARI programs with assistance from Michael De Vlieger and Charles R Greathouse IV, respectively.
STATUS
approved