Even squares k such that k-1 is divisible by a square > 1.

Terms

a(0) =64a(1) =100a(2) =576a(3) =676a(4) =784a(5) =1936a(6) =2116a(7) =2304a(8) =2500a(9) =3844a(10) =4096a(11) =5476a(12) =5776a(13) =6400a(14) =6724a(15) =9604a(16) =10000a(17) =13456a(18) =13924a(19) =14400a(20) =14884a(21) =15376a(22) =15876a(23) =17956a(24) =18496a(25) =21316a(26) =21904a(27) =23104a(28) =23716a(29) =28224