A068822 a(n) = gcd(n,c(n)), where c(n) is the 10's complement of n.

1, 2, 1, 2, 5, 2, 1, 2, 1, 10, 1, 4, 1, 2, 5, 4, 1, 2, 1, 20, 1, 2, 1, 4, 25, 2, 1, 4, 1, 10, 1, 4, 1, 2, 5, 4, 1, 2, 1, 20, 1, 2, 1, 4, 5, 2, 1, 4, 1, 50, 1, 4, 1, 2, 5, 4, 1, 2, 1, 20, 1, 2, 1, 4, 5, 2, 1, 4, 1, 10, 1, 4, 1, 2, 25, 4, 1, 2, 1, 20, 1, 2

Offset

1,2

Links

Alois P. Heinz, Table of n, a(n) for n = 1..9999

Formula

a(n) = gcd(n,A089186(n)) = gcd(n,A178914(n)). - Alois P. Heinz, Nov 05 2018

Example

a(45) = 5 as 10's complement of 45 is 100-45 = 55 and (45,55) = 5.

Maple

a:=n-> igcd((10^length(n)-n), n):
seq(a(n), n=1..100);  # Alois P. Heinz, Sep 22 2015

Mathematica

GCD[#, 10^(IntegerLength[#]) - #] & /@ Range[82] (* Jayanta Basu, Aug 07 2013 *)

Crossrefs

Cf. A089186, A178914.

Sequence in context: A135506 A295516 A330209 * A351517 A337224 A090079

Adjacent sequences: A068819 A068820 A068821 * A068823 A068824 A068825

Keyword

nonn,base,easy

Author

Amarnath Murthy, Mar 08 2002

Status

approved