A135914 a(n) = 4*3^n - 2*2^n - 1.

1, 7, 27, 91, 291, 907, 2787, 8491, 25731, 77707, 234147, 704491, 2117571, 6360907, 19099107, 57330091, 172055811, 516298507, 1549157667, 4647997291, 13945040451, 41837218507, 125515849827, 376555938091, 1129684591491, 3389087328907, 10167329095587

Offset: 0

Author

N. J. A. Sloane, Mar 07 2008

Keywords

• nonn
• easy

References

• G. S. Lueker, Some techniques for solving recurrences, Computing Surveys, 12 (1980), 419-436.

Links

• Index entries for linear recurrences with constant coefficients, signature (6,-11,6).

Crossrefs

Cf. A134067.

Programs

Mathematica

Table[4*3^n-2*2^n-1,{n,0,30}] (* or *) LinearRecurrence[{6,-11,6},{1,7,27},30] (* Harvey P. Dale, Aug 26 2019 *)

Formula

From Gary W. Adamson, Mar 08 2008: (Start)

Inverse binomial transform = A134067: (1, 6, 14, 30, 62, 126, ...).

Second inverse binomial transform = (1, 5, 3, 5, 3, 5, 3, 5, ...). (End)

From Colin Barker, Aug 13 2012: (Start)

a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3).

G.f.: (1+x-4*x^2)/((1-x)*(1-2*x)*(1-3*x)). (End)