Convolution of Catalan numbers and squares.

Terms

a(0) =0a(1) =1a(2) =5a(3) =15a(4) =38a(5) =93a(6) =236a(7) =641a(8) =1869a(9) =5779a(10) =18663a(11) =62179a(12) =211909a(13) =734651a(14) =2581317a(15) =9169247a(16) =32867726a(17) =118729269a(18) =431756336a(19) =1579232417a(20) =5806059402a(21) =21443620901a(22) =79522304354a(23) =295990940421