Squares of odd triangular numbers.

Terms

a(0) =1a(1) =9a(2) =225a(3) =441a(4) =2025a(5) =3025a(6) =8281a(7) =11025a(8) =23409a(9) =29241a(10) =53361a(11) =64009a(12) =105625a(13) =123201a(14) =189225a(15) =216225a(16) =314721a(17) =354025a(18) =494209a(19) =549081a(20) =741321a(21) =815409a(22) =1071225a(23) =1168561a(24) =1500625a(25) =1625625a(26) =2047761a(27) =2205225a(28) =2732409a(29) =2927521