A083595 a(n) = (7*2^n - 4(-1)^n)/3.

1, 6, 8, 20, 36, 76, 148, 300, 596, 1196, 2388, 4780, 9556, 19116, 38228, 76460, 152916, 305836, 611668, 1223340, 2446676, 4893356, 9786708, 19573420, 39146836, 78293676, 156587348, 313174700, 626349396, 1252698796, 2505397588

Offset: 0

Author

Paul Barry, May 02 2003

Keywords

• easy
• nonn

Comments

Binomial transform of A083594.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..238
• Index entries for linear recurrences with constant coefficients, signature (1,2).

Crossrefs

Cf. A082541.

Programs

Magma

[(7*2^n-4*(-1)^n)/3: n in [0..40]]; // Vincenzo Librandi, Apr 28 2011

Mathematica

LinearRecurrence[{1,2},{1,6},40] (* Harvey P. Dale, Aug 13 2019 *)

Formula

a(n) = (7*2^n - 4(-1)^n)/3 .

G.f.: (1+5*x)/((1-2*x)*(1+x)).

E.g.f.: (7*exp(2*x) - 4*exp(-x))/3.