Triangle read by rows giving coefficients of Bessel polynomial p_n(x).

Terms

a(0) =0a(1) =1a(2) =0a(3) =1a(4) =1a(5) =0a(6) =1a(7) =3a(8) =3a(9) =0a(10) =1a(11) =6a(12) =15a(13) =15a(14) =0a(15) =1a(16) =10a(17) =45a(18) =105a(19) =105a(20) =0a(21) =1a(22) =15a(23) =105a(24) =420a(25) =945a(26) =945a(27) =0a(28) =1a(29) =21