Triangle read by rows: T(k,n) is number of numbers <= 10^n that are products of k primes.

Terms

a(0) =4a(1) =4a(2) =1a(3) =25a(4) =34a(5) =22a(6) =12a(7) =4a(8) =2a(9) =168a(10) =299a(11) =247a(12) =149a(13) =76a(14) =37a(15) =14a(16) =7a(17) =2a(18) =1229a(19) =2625a(20) =2569a(21) =1712a(22) =963a(23) =485a(24) =231a(25) =105a(26) =47a(27) =22a(28) =7a(29) =3