Convolution of A055589 with A011782.

Terms

a(0) =0a(1) =1a(2) =7a(3) =34a(4) =138a(5) =501a(6) =1683a(7) =5336a(8) =16172a(9) =47264a(10) =134048a(11) =370688a(12) =1003136a(13) =2664192a(14) =6960384a(15) =17922048a(16) =45552640a(17) =114442240a(18) =284508160a(19) =700579840a(20) =1710161920a(21) =4141416448a(22) =9955639296a(23) =23770693632a(24) =56400543744a(25) =133041225728