OFFSET
1,2
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
Michael De Vlieger, Log log scatterplot of a(n), n = 1..2^14, accentuating prime powers in red.
MATHEMATICA
nn = 120;
c[_] := False;
Array[Set[{a[#], c[#]}, {#, True}] &, 2]; Set[{i, j, u},
Range[3]]; s = i + j;
Do[k = u;
While[Or[c[k], CoprimeQ[s, k]], k++];
Set[{a[n], c[k], i, j, s}, {s, True, j, k, j + k}];
If[k == u, While[c[u], u++]], {n, 2, nn}], n];
Array[a, nn] (* Michael De Vlieger, Oct 26 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 26 2023
STATUS
approved