A089985 a(n) = A089709(n+1)/A089709(n).

2, 3, 6, 10, 18, 34, 66, 130, 258, 514, 1026, 2050, 4098, 8194, 16386, 32770, 65538, 131074, 262146, 524290, 1048578, 2097154, 4194306, 8388610, 16777218, 33554434, 67108866, 134217730, 268435458, 536870914, 1073741826, 2147483650

Offset: 1

Author

Ray Chandler, Nov 21 2003

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..2000
• Index entries for linear recurrences with constant coefficients, signature (3, -2).

Crossrefs

Cf. A089709.

Essentially the same as A056469.

Programs

Mathematica

Join[{2,3},Rest[2^Range[40]+2]] (* Harvey P. Dale, Sep 19 2011 *)

Formula

a(n) = 2^(n-1)+2, n>2.