a(n) = Sum_{i=0..n} digsum_6(i)^3, where digsum_6(i) = A053827(i).

Terms

a(0) =0a(1) =1a(2) =9a(3) =36a(4) =100a(5) =225a(6) =226a(7) =234a(8) =261a(9) =325a(10) =450a(11) =666a(12) =674a(13) =701a(14) =765a(15) =890a(16) =1106a(17) =1449a(18) =1476a(19) =1540a(20) =1665a(21) =1881a(22) =2224a(23) =2736a(24) =2800a(25) =2925a(26) =3141a(27) =3484a(28) =3996a(29) =4725