a(n) is the index of the smallest tetrahedral number with exactly n distinct prime factors.

A359089

a(n) is the index of the smallest tetrahedral number with exactly n distinct prime factors.

Terms

    a(0) =1a(1) =2a(2) =3a(3) =7a(4) =18a(5) =34a(6) =90a(7) =259a(8) =988a(9) =2583a(10) =5795a(11) =37960a(12) =101268a(13) =424268a(14) =3344614a(15) =17168723a(16) =74282570a(17) =351200178a(18) =1082950218a(19) =5313193819a(20) =31439710664a(21) =317760710839

External references