OFFSET
1,2
LINKS
Diana Mecum, Table of n, a(n) for n = 1..1000
EXAMPLE
12 has the prime-factorization of 2^2 * 3^1. The positive integers that don't occur among the first 11 terms of the sequence are 12,13,14,15,16,... Of these integers, 13 is the smallest that is coprime to the exponents in the prime factorization of 12 (i.e., coprime to 2 and 1). So a(12) = 13.
MATHEMATICA
With[{nn = 72}, Fold[Append[#1, SelectFirst[Range[2, 2 nn], Function[k, And[FreeQ[#1, k], AllTrue[FactorInteger[#2][[All, -1]], CoprimeQ[k, #] &]]]]] &, {1}, Range[2, nn]]] (* Michael De Vlieger, Oct 18 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Mar 13 2008
EXTENSIONS
More terms from Diana L. Mecum, Jul 21 2008
STATUS
approved