Sum of squares of numbers that cannot be written as t*n + u*(n+1) for nonnegative integers t,u.

Terms

a(0) =0a(1) =1a(2) =30a(3) =220a(4) =950a(5) =3045a(6) =8036a(7) =18480a(8) =38340a(9) =73425a(10) =131890a(11) =224796a(12) =366730a(13) =576485a(14) =877800a(15) =1300160a(16) =1879656a(17) =2659905a(18) =3693030a(19) =5040700a(20) =6775230a(21) =8980741a(22) =11754380a(23) =15207600a(24) =19467500a(25) =24678225a(26) =31002426a(27) =38622780a(28) =47743570