a(n)^2 + 1 is largest prime of the form x^2 + 1 <= 10^n.

Terms

a(0) =2a(1) =6a(2) =26a(3) =94a(4) =314a(5) =986a(6) =3160a(7) =9990a(8) =31614a(9) =99996a(10) =316206a(11) =999960a(12) =3162246a(13) =9999960a(14) =31622764a(15) =99999966a(16) =316227734a(17) =999999924a(18) =3162277660a(19) =9999999956a(20) =31622776500a(21) =99999999964a(22) =316227766006a(23) =999999999886