OFFSET
1,2
COMMENTS
The sequence is conjectured to be a permutation of the positive integers, although it takes many terms for the primes to appear, e.g., a(191443) = 19.
LINKS
Scott R. Shannon, Image of the first 50000 terms. The green line is a(n) = n.
EXAMPLE
a(3) = 4 as a(1) + a(2) = 1 + 2 = 3 which does not contain 2 as a prime factor, and 4 is the smallest unused number that is a multiple of 2.
a(4) = 5 as a(2) + a(3) = 2 + 4 = 6 = 2*3 which does not contain 5 as a prime factor, and 5 is the smallest unused number that is a multiple of 5.
CROSSREFS
KEYWORD
nonn
AUTHOR
Scott R. Shannon, Mar 25 2023
STATUS
approved