a(n) = 1 + 2 * (a(n-1) + a(n-4) + a(n-6)) + a(n-7) for n>3, with initial values 0 if n<0, and 1,3,8,18 for n=0..3.
A317188
a(n) = 1 + 2 * (a(n-1) + a(n-4) + a(n-6)) + a(n-7) for n>3, with initial values 0 if n<0, and 1,3,8,18 for n=0..3.
Terms
- a(0) =1a(1) =3a(2) =8a(3) =18a(4) =39a(5) =85a(6) =189a(7) =422a(8) =942a(9) =2099a(10) =4673a(11) =10400a(12) =23148a(13) =51528a(14) =114709a(15) =255359a(16) =568460a(17) =1265450a(18) =2817015a(19) =6270953a(20) =13959773a(21) =31075874a(22) =69178058a(23) =153997383a(24) =342813793a(25) =763138256a(26) =1698823128a(27) =3781752544a(28) =8418564665a(29) =18740578667
External references
- oeis: A317188