a(1) = 1; a(n) is smallest square > a(n-1) such that a(n) + a(n-1) is a prime.

Terms

a(0) =1a(1) =4a(2) =9a(3) =64a(4) =169a(5) =400a(6) =529a(7) =900a(8) =961a(9) =1936a(10) =2401a(11) =5476a(12) =6241a(13) =6400a(14) =7921a(15) =9216a(16) =10201a(17) =10816a(18) =11025a(19) =13456a(20) =14161a(21) =15376a(22) =17161a(23) =17956a(24) =19321a(25) =19600a(26) =22201a(27) =22500a(28) =24649a(29) =24964