OFFSET
1,1
COMMENTS
The complement of A230034.
Each number beginning from 2731 is in a(n).
Generally for every positive integer k there is only finite quantity of numbers which can't be represented as a sum of k+1 relatively prime positive integers such that any k of them are not coprime.
For instance, for k = 3 570570 is the largest number which cannot be represented.
EXAMPLE
31 is in a(n) because 31 = 6 + 10 + 15 and gcd(6, 10, 15) = 1 however gcd(6, 10) = 2, gcd(6, 15) = 3, gcd(10, 15) = 5.
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Letsko, Dec 20 2013
STATUS
approved