A214587 Greatest common divisor of a number and its last decimal digit: a(n) = gcd(n, n mod 10).

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 1, 2, 5, 2, 1, 2, 1, 20, 1, 2, 1, 4, 5, 2, 1, 4, 1, 30, 1, 2, 3, 2, 5, 6, 1, 2, 3, 40, 1, 2, 1, 4, 5, 2, 1, 8, 1, 50, 1, 2, 1, 2, 5, 2, 1, 2, 1, 60, 1, 2, 3, 4, 5, 6, 1, 4, 3, 70, 1, 2, 1, 2, 5, 2, 7, 2, 1, 80, 1, 2, 1, 4, 5

Offset

0,3

Links

Table of n, a(n) for n=0..85.

Example

a(69) = gcd(69,9) = 3.

Mathematica

Table[GCD[n, Mod[n, 10]], {n, 0, 100}] (* T. D. Noe, Jul 24 2012 *)

Prog

(Java)
import java.math.BigInteger;
public class A214587 {
  public static void main (String[] args) {
    for (long n=0; n<222; n++) {
    BigInteger bn=BigInteger.valueOf(n), ld=BigInteger.valueOf(n%10);
    System.out.printf("%s, ", bn.gcd(ld).toString());
    }
  }
}

Crossrefs

Cf. A068822.

Sequence in context: A278946 A322629 A190599 * A365762 A010889 A053831

Adjacent sequences: A214584 A214585 A214586 * A214588 A214589 A214590

Keyword

nonn,base

Author

Alex Ratushnyak, Jul 22 2012

Status

approved