First differences of A057809.

Terms

a(0) =2a(1) =2a(2) =2a(3) =19a(4) =3a(5) =3a(6) =63a(7) =4a(8) =20a(9) =210a(10) =5a(11) =5a(12) =10a(13) =5a(14) =5a(15) =648a(16) =72a(17) =12a(18) =24a(19) =6a(20) =6a(21) =6a(22) =1925a(23) =7a(24) =7a(25) =7a(26) =7a(27) =7a(28) =5314a(29) =16