A066750 Greatest common divisor of n and its digit sum.

1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 1, 3, 1, 1, 3, 1, 1, 9, 1, 2, 3, 2, 1, 6, 1, 2, 9, 2, 1, 3, 1, 1, 3, 1, 1, 9, 1, 1, 3, 4, 1, 6, 1, 4, 9, 2, 1, 12, 1, 5, 3, 1, 1, 9, 5, 1, 3, 1, 1, 6, 1, 2, 9, 2, 1, 6, 1, 2, 3, 7, 1, 9, 1, 1, 3, 1, 7, 3, 1, 8, 9, 2, 1, 12, 1, 2, 3, 8, 1, 9

Offset: 1

Author

Reinhard Zumkeller, Jan 16 2002

Keywords

• nonn
• base

Comments

a(n) = 1 iff n is in A339076. - Bernard Schott, Jan 17 2022

Links

• Harry J. Smith, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A007953, A339076.

Programs

Mathematica

Table[GCD[n,Total[IntegerDigits[n]]],{n,100}] (* Harvey P. Dale, Aug 13 2015 *)

PARI

a(n) = gcd(n, sumdigits(n)); \\ Michel Marcus, Jan 17 2022

Python

from math import gcd
def A066750(n): return gcd(n,sum(int(d) for d in str(n))) # Chai Wah Wu, Jan 26 2022