a(n) = 19*2^n.

Terms

a(0) =19a(1) =38a(2) =76a(3) =152a(4) =304a(5) =608a(6) =1216a(7) =2432a(8) =4864a(9) =9728a(10) =19456a(11) =38912a(12) =77824a(13) =155648a(14) =311296a(15) =622592a(16) =1245184a(17) =2490368a(18) =4980736a(19) =9961472a(20) =19922944a(21) =39845888a(22) =79691776a(23) =159383552a(24) =318767104a(25) =637534208a(26) =1275068416a(27) =2550136832a(28) =5100273664a(29) =10200547328