Prime factors occurring in the norms given in S000949.
2, 3, 5, 13, 37, 41, 53, 61, 113, 157
1
Except for 2 and 3, these are all of the form 4k+1. If S000949 is extended, other prime factors may appear.
T. D. Noe, Plot of 10 terms
(Mma) (* let tn contain the numbers in S000949 *) Union[Flatten[Table[Transpose[FactorInteger[n]][[1]], {n, tn}]]]
Cf. S000949.
nonn,more
T. D. Noe, Oct 06 2016