A078453 Numbers in which all the digits are coprime to each other.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 23, 25, 27, 29, 31, 32, 34, 35, 37, 38, 41, 43, 45, 47, 49, 51, 52, 53, 54, 56, 57, 58, 59, 61, 65, 67, 71, 72, 73, 74, 75, 76, 78, 79, 81, 83, 85, 87, 89, 91, 92, 94, 95, 97, 98

Offset: 1

Author

Amarnath Murthy, Nov 28 2002

Keywords

• base
• easy
• nonn

Crossrefs

Cf. A069715.

Programs

Mathematica

Join[Range[0,9],Select[Range[10,98],GCD@@IntegerDigits[#]==1 &]] (* Stefano Spezia, Dec 23 2022 *)

Python

from math import gcd
from functools import reduce
def ok(n):
    d = list(map(int, str(n)))
    return len(d) == 1 or reduce(gcd, d) == 1
print([k for k in range(100) if ok(k)]) # Michael S. Branicky, Dec 23 2022