a(n) = A066186(n) - A004125(n).

Terms

a(0) =1a(1) =4a(2) =8a(3) =19a(4) =31a(5) =63a(6) =97a(7) =168a(8) =258a(9) =407a(10) =594a(11) =907a(12) =1285a(13) =1859a(14) =2604a(15) =3660a(16) =4998a(17) =6883a(18) =9246a(19) =12479a(20) =16562a(21) =21967a(22) =28767a(23) =37715a(24) =48847a(25) =63224a(26) =81145a(27) =103980a(28) =132234a(29) =167982