Stirling2 triangle with scaled diagonals (powers of 3).

Terms

a(0) =1a(1) =3a(2) =1a(3) =9a(4) =9a(5) =1a(6) =27a(7) =63a(8) =18a(9) =1a(10) =81a(11) =405a(12) =225a(13) =30a(14) =1a(15) =243a(16) =2511a(17) =2430a(18) =585a(19) =45a(20) =1a(21) =729a(22) =15309a(23) =24381a(24) =9450a(25) =1260a(26) =63a(27) =1a(28) =2187a(29) =92583