Irregular triangle read by rows: coefficients of polynomials related to Stirling permutations.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =3a(6) =7a(7) =3a(8) =1a(9) =1a(10) =7a(11) =29a(12) =31a(13) =29a(14) =7a(15) =1a(16) =1a(17) =15a(18) =101a(19) =195a(20) =321a(21) =195a(22) =101a(23) =15a(24) =1a(25) =1a(26) =31a(27) =327a(28) =1001a(29) =2507