a(n) = integer nearest e*a(n-1), where a(0) = 1.

Terms

a(0) =1a(1) =3a(2) =8a(3) =22a(4) =60a(5) =163a(6) =443a(7) =1204a(8) =3273a(9) =8897a(10) =24185a(11) =65742a(12) =178705a(13) =485771a(14) =1320462a(15) =3589388a(16) =9756968a(17) =26522189a(18) =72094784a(19) =195973941a(20) =532712403a(21) =1448062445a(22) =3936241831a(23) =10699814642a(24) =29085111709a(25) =79061530637a(26) =214911522061a(27) =584190085145