Eigensequence of triangle A054142.

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =24a(5) =122a(6) =758a(7) =5606a(8) =48378a(9) =479532a(10) =5390940a(11) =68022932a(12) =954948752a(13) =14804391270a(14) =251815549396