OFFSET
2,1
LINKS
Rémy Sigrist, Table of n, a(n) for n = 2..10000
EXAMPLE
6_10 (6 in decimal) is 110_2 (110 in binary). 9_10 = 1001_2, which contains the same number of ones in the binary expansion. 9 isn't coprime to 6; they share prime factor 3 and 9 isn't a divisor of 6. No positive integer less than 9 has these properties. Therefore, a(6) = 9.
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Leroy Quet, Jun 09 2009
EXTENSIONS
Offset corrected and more terms from Rémy Sigrist, Apr 15 2017
STATUS
approved