OFFSET
1,1
COMMENTS
Are there any composites in this sequence? If not, is this sequence a permutation of the primes?
This sequence is a permutation of the primes. See links. - Alain Rousseau, Oct 25 2023
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..1000 (first 100 terms from Andrew V. Sutherland)
les-mathematiques.net, Les suites A139317 & A132948
Andrew V. Sutherland, Comments on A139317 and A139319
EXAMPLE
For a(7) we check: 7*1 +1= 8, which is not coprime to a(1)=2. 7*2 +1= 15, which is not coprime to either a(2)=3 or to a(4)=5. 7*3 +1 = 22, which is not coprime to either a(1)=2 or to a(5)=11. But 7*4+1 = 29, which is coprime to terms a(1) through a(6). So a(7) = 29.
MATHEMATICA
Fold[Append[#1, SelectFirst[#2 Range@ 120 + 1, Function[k, CoprimeQ @@ Append[#1, k]]]] &, {2}, Range[2, 56]] (* Michael De Vlieger, Oct 22 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Apr 13 2008
STATUS
approved