Coefficient triangle of the modified Hermite-Bell polynomials for power -2.

Terms

a(0) =1a(1) =1a(2) =2a(3) =-3a(4) =2a(5) =-9a(6) =6a(7) =4a(8) =-36a(9) =75a(10) =-30a(11) =4a(12) =-60a(13) =255a(14) =-330a(15) =90a(16) =8a(17) =-180a(18) =1290a(19) =-3465a(20) =3150a(21) =-630a(22) =8a(23) =-252a(24) =2730a(25) =-12495a(26) =23940a(27) =-16380a(28) =2520a(29) =16