Least square n-gonal number greater than 1, or 0 if none exists.

Terms

a(0) =36a(1) =4a(2) =9801a(3) =1225a(4) =81a(5) =225a(6) =9a(7) =0a(8) =196a(9) =64a(10) =36a(11) =441a(12) =3025a(13) =16a(14) =17689a(15) =100a(16) =484a(17) =0a(18) =2601a(19) =729a(20) =68121a(21) =225a(22) =25a(23) =7225a(24) =25921a(25) =81a(26) =1225a(27) =203401a(28) =441a(29) =1089