a(n) = Sum_{i=0..n} digsum_4(i)^3, where digsum_4(i) = A053737(i).

Terms

a(0) =0a(1) =1a(2) =9a(3) =36a(4) =37a(5) =45a(6) =72a(7) =136a(8) =144a(9) =171a(10) =235a(11) =360a(12) =387a(13) =451a(14) =576a(15) =792a(16) =793a(17) =801a(18) =828a(19) =892a(20) =900a(21) =927a(22) =991a(23) =1116a(24) =1143a(25) =1207a(26) =1332a(27) =1548a(28) =1612a(29) =1737