Squares whose second arithmetic derivative is a square.

Terms

a(0) =0a(1) =1a(2) =4a(3) =49a(4) =529a(5) =2209a(6) =6241a(7) =27889a(8) =28561a(9) =35344a(10) =49729a(11) =128881a(12) =192721a(13) =250000a(14) =431649a(15) =528529a(16) =703921a(17) =1181569a(18) =1495729a(19) =1610361a(20) =1868689a(21) =3411409a(22) =4870849a(23) =5755201a(24) =9138529a(25) =11390625a(26) =12250000a(27) =13830961a(28) =13845841a(29) =15737089