OFFSET
0,2
LINKS
Michael De Vlieger, Table of n, a(n) for n = 0..10000
MAPLE
A163643 := proc(n) if n = 0 then 1; else for a from procname(n-1)+1 do if not isprime(a) then if gcd(a, n) = 1 then return a; end if; end if; end do: end if; end proc: seq(A163643(n), n=0..100) ; # R. J. Mathar, Oct 09 2010
MATHEMATICA
a = {4}; Do[k = a[[n]] + 1; While[Nand[CompositeQ@ k, ! MemberQ[a, k], CoprimeQ[k, n + 1]], k++]; AppendTo[a, k], {n, 61}]; {1}~Join~a (* Michael De Vlieger, Jul 23 2017 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Leroy Quet, Aug 02 2009
EXTENSIONS
More terms from R. J. Mathar, Oct 09 2010
STATUS
approved