Row 3 of rectangular table A124530.

Terms

a(0) =1a(1) =1a(2) =4a(3) =16a(4) =71a(5) =351a(6) =1891a(7) =10888a(8) =66139a(9) =420235a(10) =2775981a(11) =18978873a(12) =133828922a(13) =970678790a(14) =7226115267a(15) =55115404005a(16) =430080085093