A242475 a(n) = 2^n + 8.

9, 10, 12, 16, 24, 40, 72, 136, 264, 520, 1032, 2056, 4104, 8200, 16392, 32776, 65544, 131080, 262152, 524296, 1048584, 2097160, 4194312, 8388616, 16777224, 33554440, 67108872, 134217736, 268435464, 536870920, 1073741832

Offset: 0

Author

Vincenzo Librandi, May 20 2014

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (3,-2).

Crossrefs

Cf. A000051, A052548, A062709, A140504, A168614, A153972, A168415, A188165.

Programs

Magma

[2^n+8: n in [0..40]];

Mathematica

Table[2^n + 8, {n, 0, 40}] (* or *) CoefficientList[Series[(9 - 17 x)/((1 - x) (1 - 2 x)),{x, 0, 30}], x]
LinearRecurrence[{3,-2},{9,10},40] (* Harvey P. Dale, May 21 2025 *)

Formula

G.f.: (9 - 17*x)/((1 - x)*(1 - 2*x)).

a(n) = 2*a(n-1) - 8 = 3*a(n-1) - 2*a(n-2).

a(n) = A052548(n)+6 = A140504(n)+4 = A153972(n)+2.

E.g.f.: exp(2*x) + 8*exp(x). - Elmo R. Oliveira, Nov 11 2023