A084569 Partial sums of A084570.

1, 3, 9, 21, 44, 82, 142, 230, 355, 525, 751, 1043, 1414, 1876, 2444, 3132, 3957, 4935, 6085, 7425, 8976, 10758, 12794, 15106, 17719, 20657, 23947, 27615, 31690, 36200, 41176, 46648, 52649, 59211, 66369, 74157, 82612, 91770, 101670, 112350, 123851

Offset

0,2

Links

Table of n, a(n) for n=0..40.

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

Sequence in context: A011843 A080549 A175006 * A192970 A110964 A107351

Adjacent sequences: A084566 A084567 A084568 * A084570 A084571 A084572

Keyword

easy,nonn

Author

Paul Barry, May 31 2003

Status

approved