Truncated cube numbers.

Terms

a(0) =1a(1) =56a(2) =311a(3) =920a(4) =2037a(5) =3816a(6) =6411a(7) =9976a(8) =14665a(9) =20632a(10) =28031a(11) =37016a(12) =47741a(13) =60360a(14) =75027a(15) =91896a(16) =111121a(17) =132856a(18) =157255a(19) =184472a(20) =214661a(21) =247976a(22) =284571a(23) =324600a(24) =368217a(25) =415576a(26) =466831a(27) =522136a(28) =581645a(29) =645512