Partial sums of A001394.

Terms

a(0) =1a(1) =5a(2) =17a(3) =53a(4) =161a(5) =485a(6) =1433a(7) =4229a(8) =12425a(9) =36485a(10) =106673a(11) =311957a(12) =909953a(13) =2654501a(14) =7728401a(15) =22503053a(16) =65425505a(17) =190239989a(18) =552507641a(19) =1604779373a(20) =4656679889