Row sums of exponential Riordan array [1+x*tan(x/2),x], A166353.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =8a(5) =16a(6) =34a(7) =78a(8) =200a(9) =568a(10) =1806a(11) =6282a(12) =24052a(13) =99100a(14) =443178a(15) =2107966a(16) =10775664a(17) =58092112a(18) =334087750a(19) =2012990930a(20) =12863046636a(21) =85662585604a(22) =602124105122