a(n) = A104350(n) - 1.

Terms

a(0) =0a(1) =1a(2) =5a(3) =11a(4) =59a(5) =179a(6) =1259a(7) =2519a(8) =7559a(9) =37799a(10) =415799a(11) =1247399a(12) =16216199a(13) =113513399a(14) =567566999a(15) =1135133999a(16) =19297277999a(17) =57891833999