A124746 Expansion of (1+x^2)/(1-x^4+x^5).

1, 0, 1, 0, 1, -1, 1, -1, 1, -2, 2, -2, 2, -3, 4, -4, 4, -5, 7, -8, 8, -9, 12, -15, 16, -17, 21, -27, 31, -33, 38, -48, 58, -64, 71, -86, 106, -122, 135, -157, 192, -228, 257, -292, 349, -420, 485, -549, 641, -769, 905, -1034, 1190, -1410, 1674, -1939, 2224, -2600

Offset

0,10

Links

Paolo Xausa, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (0,0,0,1,-1).

Formula

a(n) = Sum_{k=0..floor(n/2)} C(floor(k/2),n-2k)*(-1)^n.

a(n) = (-1)^n*A124789(n). - R. J. Mathar, Jun 30 2020

Mathematica

LinearRecurrence[{0, 0, 0, 1, -1}, {1, 0, 1, 0, 1}, 100] (* Paolo Xausa, Aug 27 2024 *)

Crossrefs

Diagonal sums of A124744.

Cf. A124789.

Sequence in context: A035451 A363337 A304633 * A124789 A103372 A029082

Adjacent sequences: A124743 A124744 A124745 * A124747 A124748 A124749

Keyword

easy,sign

Author

Paul Barry, Nov 06 2006

Status

approved