Third column of A027447.

Terms

a(0) =4a(1) =37a(2) =1489a(3) =2059a(4) =128431a(5) =621139a(6) =6527971a(7) =7435423a(8) =1005856303a(9) =1108515013a(10) =204122194357a(11) =220369102177a(12) =236110035385