a(n) is the smallest m > n such that n^2 + 1 divides m^2 + 1.

Terms

a(0) =1a(1) =3a(2) =3a(3) =7a(4) =13a(5) =21a(6) =31a(7) =43a(8) =18a(9) =73a(10) =91a(11) =111a(12) =17a(13) =47a(14) =183a(15) =211a(16) =241a(17) =133a(18) =57a(19) =343a(20) =381a(21) =47a(22) =172a(23) =83a(24) =553a(25) =601a(26) =651a(27) =173a(28) =342a(29) =813