a(n) = |Stirling1(2*n + 1, n)|.A367777a(n) = |Stirling1(2*n + 1, n)|.Terms a(0) =0a(1) =2a(2) =50a(3) =1624a(4) =67284a(5) =3416930a(6) =206070150a(7) =14409322928External referencesoeis: A367777