Central coefficients of number triangle A119326.

Terms

a(0) =0a(1) =1a(2) =1a(3) =7a(4) =31a(5) =106a(6) =386a(7) =1499a(8) =5755a(9) =21886a(10) =83854a(11) =323302a(12) =1248534a(13) =4828916a(14) =18719364a(15) =72711123a(16) =282867795a(17) =1101981430a(18) =4298723990a(19) =16788997874a(20) =65641296578a(21) =256895812108