Squares of odd heptagonal numbers.

Terms

a(0) =1a(1) =49a(2) =3025a(3) =6561a(4) =35721a(5) =55225a(6) =162409a(7) =219961a(8) =485809a(9) =613089a(10) =1147041a(11) =1385329a(12) =2325625a(13) =2725801a(14) =4239481a(15) =4862025a(16) =7144929a(17) =8059921a(18) =11336689a(19) =12623809a(20) =17147881a(21) =18896409a(22) =24950025a(23) =27258841a(24) =35153041a(25) =38130625a(26) =48205249a(27) =51969681a(28) =64593369a(29) =69272329