A199111 a(n) = 8*3^n + 1.

9, 25, 73, 217, 649, 1945, 5833, 17497, 52489, 157465, 472393, 1417177, 4251529, 12754585, 38263753, 114791257, 344373769, 1033121305, 3099363913, 9298091737, 27894275209, 83682825625, 251048476873, 753145430617, 2259436291849, 6778308875545, 20334926626633, 61004779879897

Offset: 0

Author

Vincenzo Librandi, Nov 03 2011

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (4,-3).

Crossrefs

Cf. A000244, A005051, A160173. - Omar E. Pol, Nov 18 2011

Cf. A198644.

Programs

Magma

[8*3^n+1: n in [0..30]];

Formula

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

a(n) = 4*a(n-1) - 3*a(n-2).

G.f.: (9-11*x)/((1-x)*(1-3*x)). - Bruno Berselli, Nov 03 2011

a(n) = 8*A000244(n) + 1 = A005051(n) + 1. - Omar E. Pol, Nov 18 2011

From Elmo R. Oliveira, May 07 2025: (Start)

E.g.f.: exp(x)*(8*exp(2*x) + 1).

a(n) = A198644(n) + 2. (End)