a(n)=A074639(A074647(n)).

Terms

a(0) =0a(1) =0a(2) =1a(3) =5a(4) =11a(5) =31a(6) =75a(7) =91a(8) =145a(9) =225a(10) =241a(11) =319a(12) =419a(13) =599a(14) =727a(15) =949a(16) =803a(17) =1115a(18) =1353a(19) =1219a(20) =1869a(21) =2085a(22) =2285a(23) =2583a(24) =3101a(25) =4347a(26) =4683a(27) =5009a(28) =5921a(29) =5717