A035139 Digits of prime factors of k do not appear in k.

1, 4, 6, 8, 9, 10, 14, 16, 18, 21, 27, 34, 38, 40, 44, 46, 48, 49, 54, 56, 57, 58, 60, 64, 66, 68, 69, 76, 78, 80, 81, 84, 86, 87, 88, 90, 96, 98, 99, 100, 106, 108, 111, 116, 118, 129, 134, 140, 144, 146, 148, 158, 160, 161, 166, 168, 174, 177, 180, 184, 188, 189, 196

Offset

1,2

Links

Michael S. Branicky, Table of n, a(n) for n = 1..10000

Example

161 = 7 * 23 since {2,3,7} and {1,6} are separate digit sets.

Maple

q:= n-> (f-> is(map(f, numtheory[factorset](n)) intersect
        {f(n)}={}))(d-> convert(d, base, 10)[]):
select(q, [$1..200])[];  # Alois P. Heinz, Oct 11 2021

Mathematica

Fac[n_] := Flatten[IntegerDigits[Take[FactorInteger[n], All, 1]]]; t={1}; Do[ If[!PrimeQ[n] && Intersection[Fac[n], IntegerDigits[n]] == {}, AppendTo[t, n]], {n, 2, 196}]; t (* Jayanta Basu, May 02 2013 *)

Prog

(Magma) [k:k in [1..200]| forall{a: a in PrimeDivisors(k)|Set(Intseq(a)) meet Set(Intseq(k)) eq {}}]; // Marius A. Burtea, Oct 08 2019
(Python)
from sympy import factorint
def ok(n):
    return set(str(n)) & set("".join(str(p) for p in factorint(n))) == set()
print(list(filter(ok, range(1601))))  # Michael S. Branicky, Oct 11 2021
(PARI) digsf(n) = my(f=factor(n), list=List()); for (k=1, #f~, my(dk=digits(f[k, 1])); for (i=1, f[k, 2], for (j=1, #dk, listput(list, dk[j])))); Vec(list);
isok(m) = my(df=digsf(m), d=digits(m)); (#setintersect(Set(df), Set(d)) == 0); \\ Michel Marcus, Oct 11 2021

Crossrefs

Cf. A035140, A035141.

Sequence in context: A359982 A276628 A050695 * A316227 A062115 A141613

Adjacent sequences: A035136 A035137 A035138 * A035140 A035141 A035142

Keyword

nonn,base

Author

Patrick De Geest, Nov 15 1998

Extensions

Offset corrected and a(1) added by Giovanni Resta, May 02 2013

Status

approved