A369404 a(n) = 3*2^n + 5*(-1)^n.

8, 1, 17, 19, 53, 91, 197, 379, 773, 1531, 3077, 6139, 12293, 24571, 49157, 98299, 196613, 393211, 786437, 1572859, 3145733, 6291451, 12582917, 25165819, 50331653, 100663291, 201326597, 402653179, 805306373, 1610612731, 3221225477, 6442450939, 12884901893

Offset: 0

Author

Philippe Deléham, Jan 22 2024

Keywords

• nonn
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (1, 2).

Crossrefs

Cf. A000079, A001045, A014551, A033999.

Programs

Mathematica

LinearRecurrence[{1,2},{8,1},33] (* James C. McMahon, Jan 31 2024 *)

Python

def A369404(n): return (3<Chai Wah Wu, Feb 25 2024

Formula

a(n) = 3*A000079(n) + 5*A033999(n).

a(n) = 4*A014551(n) - 3*A001045(n).

a(n) = a(n-1) + 2*a(n-2).

G.f.: (8 - 7*x)/((1 + x)*(1 - 2*x)).