Boustrophedon transform of composite numbers.

Terms

a(0) =4a(1) =10a(2) =24a(3) =59a(4) =162a(5) =526a(6) =2016a(7) =8978a(8) =45696a(9) =261760a(10) =1666308a(11) =11668652a(12) =89141580a(13) =737740174a(14) =6575238599a(15) =62788901290a(16) =639562492327