a(n) = a(n-2) + a(n-1) if that sum is prime. Otherwise, a(n) = a(n-2) + a(n-1) + prime(m-1) + prime(m-2) + ... + prime(s), where a(-1) = a(0) = prime(0) = 1, m = pi(a(n-2)), and s = max(0, 1, 2, ..., m-1) such that the sum is prime.
A337347
a(n) = a(n-2) + a(n-1) if that sum is prime. Otherwise, a(n) = a(n-2) + a(n-1) + prime(m-1) + prime(m-2) + ... + prime(s), where a(-1) = a(0) = prime(0) = 1, m = pi(a(n-2)), and s = max(0, 1, 2, ..., m-1) such that the sum is prime.
Terms
- a(0) =2a(1) =3a(2) =5a(3) =11a(4) =19a(5) =37a(6) =73a(7) =193a(8) =337a(9) =1741a(10) =5851a(11) =39157a(12) =50857a(13) =987713a(14) =1292701a(15) =11168887a(16) =21510131a(17) =177872951a(18) =220893209a(19) =932384951a(20) =15511295531a(21) =43482833879a(22) =974160518137
External references
- oeis: A337347