Squares of even pentagonal pyramidal numbers.

Terms

a(0) =0a(1) =36a(2) =324a(3) =1600a(4) =15876a(5) =38416a(6) =82944a(7) =302500a(8) =527076a(9) =876096a(10) =2160900a(11) =3240000a(12) =4734976a(13) =9474084a(14) =13032100a(15) =17640000a(16) =30980356a(17) =40297104a(18) =51840000a(19) =83283876a(20) =104162436a(21) =129231424a(22) =194602500a(23) =236421376a(24) =285474816a(25) =409252900a(26) =486202500