a(n) = least k such that the average number of divisors of {1..k} is >= n.

Terms

a(0) =1a(1) =4a(2) =15a(3) =42a(4) =120a(5) =336a(6) =930a(7) =2548a(8) =6930a(9) =18870a(10) =51300a(11) =139440a(12) =379080a(13) =1030484a(14) =2801202a(15) =7614530a(16) =20698132a(17) =56264040a(18) =152941824a(19) =415739030a(20) =1130096128a(21) =3071920000a(22) =8350344420a(23) =22698590508a(24) =61701166395a(25) =167721158286a(26) =455913379324