Denominators of poly-Bernoulli numbers B_n^(k) with k=2.

Terms

a(0) =1a(1) =4a(2) =36a(3) =24a(4) =450a(5) =40a(6) =2205a(7) =168a(8) =350a(9) =120a(10) =38115a(11) =88a(12) =40990950a(13) =10920a(14) =5005a(15) =24a(16) =130180050a(17) =136a(18) =1935088155a(19) =3192a(20) =177827650a(21) =1320a(22) =1539340803a(23) =184a(24) =304521767550a(25) =10920a(26) =37182145a(27) =24a(29) =1160