Row sums of array in A055450.

Terms

a(0) =1a(1) =4a(2) =13a(3) =47a(4) =173a(5) =678a(6) =2735a(7) =11378a(8) =48279a(9) =208410a(10) =911571a(11) =4031919a(12) =17999628a(13) =81000573a(14) =367040404a(15) =1673295419a(16) =7669312343a(17) =35319197637a(18) =163350479756a(19) =758406642839