Central column of Pascal's "rhombus" (actually a triangle) A059317.

Terms

a(0) =1a(1) =1a(2) =4a(3) =9a(4) =29a(5) =82a(6) =255a(7) =773a(8) =2410a(9) =7499a(10) =23575a(11) =74298a(12) =235325a(13) =747407a(14) =2381126a(15) =7603433a(16) =24332595a(17) =78013192a(18) =250540055a(19) =805803691a(20) =2595158718a(21) =8368026845a(22) =27012184877a(23) =87283372610a(24) =282294378071a(25) =913775677281