Central coefficients of the triangle A132047.

Terms

a(0) =1a(1) =6a(2) =18a(3) =60a(4) =210a(5) =756a(6) =2772a(7) =10296a(8) =38610a(9) =145860a(10) =554268a(11) =2116296a(12) =8112468a(13) =31201800a(14) =120349800a(15) =465352560a(16) =1803241170a(17) =7000818660a(18) =27225405900a(19) =106035791400a(20) =413539586460