Triangle read by rows: number of topologically distinct sets of n circles with one pair intersecting, by number of factors.

A280787

Triangle read by rows: number of topologically distinct sets of n circles with one pair intersecting, by number of factors.

Terms

    a(0) =1a(1) =3a(2) =1a(3) =10a(4) =4a(5) =1a(6) =30a(7) =15a(8) =4a(9) =1a(10) =91a(11) =50a(12) =16a(13) =4a(14) =1a(15) =268a(16) =162a(17) =55a(18) =16a(19) =4a(20) =1a(21) =790a(22) =506a(23) =185a(24) =56a(25) =16a(26) =4a(27) =1a(28) =2308a(29) =1558

External references