Powerful numbers of the form k^2 - 1.

Terms

a(0) =8a(1) =288a(2) =675a(3) =9800a(4) =235224a(5) =332928a(6) =1825200a(7) =11309768a(8) =384199200a(9) =592192224a(10) =4931691075a(11) =13051463048a(12) =221322261600a(13) =443365544448a(14) =865363202000