A058529(n+1)^2.

Terms

a(0) =49a(1) =289a(2) =529a(3) =961a(4) =1681a(5) =2209a(6) =2401a(7) =5041a(8) =5329a(9) =6241a(10) =7921a(11) =9409a(12) =10609a(13) =12769a(14) =14161a(15) =16129a(16) =18769a(17) =22801a(18) =25921a(19) =27889a(20) =36481a(21) =37249a(22) =39601a(23) =47089a(24) =49729a(25) =54289a(26) =57121a(27) =58081a(28) =66049a(29) =69169