OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (4, -5, 0, 5, -4, 1).
FORMULA
a(n)=(-1)^n/8 + (n^4+6n^3+17n^2+30n+21)/24; a(n)=sum(sum(sum(i+(-1)^i, i, 0, j), j, 0, k), k, 0, n).
MATHEMATICA
Accumulate[LinearRecurrence[{3, -2, -2, 3, -1}, {1, 2, 6, 12, 23}, 50]] (* or *) LinearRecurrence[{4, -5, 0, 5, -4, 1}, {1, 3, 9, 21, 44, 82}, 50] (* Harvey P. Dale, Nov 12 2014 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, May 31 2003
STATUS
approved