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
KEYWORD
sign
AUTHOR
EXTENSIONS
More terms from Vladimir Joseph Stephan Orlovsky, Apr 25 2010
STATUS
approved