Number of "abc-hits" with c < 10^n.

Terms

a(0) =1a(1) =6a(2) =31a(3) =120a(4) =418a(5) =1268a(6) =3499a(7) =8987a(8) =22316a(9) =51677a(10) =116978a(11) =252856a(12) =528275a(13) =1075319a(14) =2131671a(15) =4119410a(16) =7801334a(17) =14482065