The primes occurring in S000904 as the constant k1.
5, 13, 71, 137, 251, 661, 1871, 3643, 5827, 10039, 19237, 40129, 38197, 40459, 225347
1
Note that the 12-th term is lower than the 11-th.
T. D. Noe, Plot of 15 terms
(Mma) (* see the program for S000904 *)
nonn,hard
T. D. Noe, Jun 15 2016