a(n) = 2^n*pentanacci(n) or (2^n)*A023424(n-1).

Terms

a(0) =2a(1) =12a(2) =56a(3) =240a(4) =992a(5) =3648a(6) =14464a(7) =57088a(8) =224768a(9) =883712a(10) =3471360a(11) =13651968a(12) =53682176a(13) =211075072a(14) =829915136a(15) =3263102976a(16) =12830244864a(17) =50447253504a(18) =198353354752a(19) =779904614400