Squares of even heptagonal numbers.

Terms

a(0) =0a(1) =324a(2) =1156a(3) =12544a(4) =21904a(5) =81796a(6) =116964a(7) =291600a(8) =379456a(9) =763876a(10) =940900a(11) =1658944a(12) =1971216a(13) =3175524a(14) =3678724a(15) =5550736a(16) =6310144a(17) =9060100a(18) =10150596a(19) =14017536a(20) =15523600a(21) =20775364a(22) =22791076a(23) =29724304a(24) =32353344a(25) =41293476a(26) =44649124a(27) =55950400a(28) =60155536a(29) =74200996