Sums of the antidiagonals of the table of k-almost primes (A078840).

Terms

a(0) =1a(1) =2a(2) =7a(3) =19a(4) =44a(5) =95a(6) =195a(7) =395a(8) =794a(9) =1583a(10) =3172a(11) =6334a(12) =12665a(13) =25313a(14) =50596a(15) =101180a(16) =202326a(17) =404635a(18) =809227a(19) =1618410a(20) =3236766a(21) =6473474a(22) =12946903a(23) =25893723a(24) =51787365a(25) =103574668a(26) =207149213a(27) =414298342a(28) =828596584a(29) =1657193052