A014846 2^(n-1) - n*(n+1)/2.

0, -1, -2, -2, 1, 11, 36, 92, 211, 457, 958, 1970, 4005, 8087, 16264, 32632, 65383, 130901, 261954, 524078, 1048345, 2096899, 4194028, 8388308, 16776891, 33554081, 67108486, 134217322, 268435021, 536870447, 1073741328, 2147483120

Offset

1,3

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Index entries for linear recurrences with constant coefficients, signature (5, -9, 7, -2).

Formula

a(0)=0, a(1)=-1, a(2)=-2, a(3)=-2, a(n)=5*a(n-1)-9*a(n-2)+7*a(n-3)-2*a(n-4). - Harvey P. Dale, Aug 02 2011

Mathematica

Table[2^n-n*(n+1), {n, 50}]/2 (* Vladimir Joseph Stephan Orlovsky, Apr 25 2010 *)
LinearRecurrence[{5, -9, 7, -2}, {0, -1, -2, -2}, 50] (* Harvey P. Dale, Aug 02 2011 *)

Prog

(Magma) [2^(n-1) - n*(n+1)/2: n in [1..35]]; // Vincenzo Librandi, Jul 28 2011

Crossrefs

Sequence in context: A327087 A088876 A346078 * A100942 A132471 A130528

Adjacent sequences: A014843 A014844 A014845 * A014847 A014848 A014849

Keyword

sign

Author

N. J. A. Sloane

Extensions

More terms from Vladimir Joseph Stephan Orlovsky, Apr 25 2010

Status

approved