a(n) is the least prime p such that n^2 + (p-n)^2 is prime and k^2 + (p-k)^2 is composite for 1 <= k < n.
A376920
a(n) is the least prime p such that n^2 + (p-n)^2 is prime and k^2 + (p-k)^2 is composite for 1 <= k < n.
Terms
- a(0) =2a(1) =19a(2) =13a(3) =53a(4) =31a(5) =71a(6) =109a(7) =263a(8) =239a(9) =167a(10) =661a(11) =439a(12) =673a(13) =1289a(14) =1021a(15) =2531a(16) =3617a(17) =5101a(18) =1033a(19) =3037a(20) =2017a(21) =4889a(22) =4751a(23) =3169a(24) =887a(25) =2521a(26) =11467a(27) =20143a(28) =563a(29) =1873
External references
- oeis: A376920