Odd terms in A305236.

Terms

a(0) =63a(1) =513a(2) =2107a(3) =12625a(4) =26533a(5) =39609a(6) =355023a(7) =3190833a(8) =4457713a(9) =19854847a(10) =38463283a(11) =242138449a(12) =370634743a(13) =516465451a(14) =574336561a(15) =701607583a(16) =1380336193a(17) =2324581983a(18) =4882890625a(19) =6174434113a(20) =12859758577a(21) =14793096853a(22) =20578440583a(23) =43522669657a(24) =85504120021