Triangle of Stirling numbers of the second kind, S2(n,k), n >= 1, 1 <= k <= n.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =1a(6) =1a(7) =7a(8) =6a(9) =1a(10) =1a(11) =15a(12) =25a(13) =10a(14) =1a(15) =1a(16) =31a(17) =90a(18) =65a(19) =15a(20) =1a(21) =1a(22) =63a(23) =301a(24) =350a(25) =140a(26) =21a(27) =1a(28) =1a(29) =127