Triangle read by rows: 2-Stirling numbers of the second kind.

Terms

a(0) =1a(1) =2a(2) =1a(3) =4a(4) =5a(5) =1a(6) =8a(7) =19a(8) =9a(9) =1a(10) =16a(11) =65a(12) =55a(13) =14a(14) =1a(15) =32a(16) =211a(17) =285a(18) =125a(19) =20a(20) =1a(21) =64a(22) =665a(23) =1351a(24) =910a(25) =245a(26) =27a(27) =1a(28) =128a(29) =2059