A124745 Expansion of (1+x)/(1-x^2+x^3).

1, 1, 1, 0, 0, -1, 0, -1, 1, -1, 2, -2, 3, -4, 5, -7, 9, -12, 16, -21, 28, -37, 49, -65, 86, -114, 151, -200, 265, -351, 465, -616, 816, -1081, 1432, -1897, 2513, -3329, 4410, -5842, 7739, -10252, 13581, -17991, 23833, -31572

Offset

0,11

Comments

Row sums of A124744.

Links

Table of n, a(n) for n=0..45.

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

Formula

a(n) = Sum_{k=0..n} C(floor(k/2),n-k)*(-1)^(n-k) = (-1)^n*A078027(n).

a(n) = a(n-2) - a(n-3) with a(1) = a(2) = a(3) = 1. - Taras Goy, Mar 24 2019

Crossrefs

The following are basically all variants of the same sequence: A000931, A078027, A096231, A124745, A133034, A134816, A164001, A182097, A228361 and probably A020720. However, each one has its own special features and deserves its own entry.

Sequence in context: A274200 A018052 A018124 * A133034 A000931 A078027

Adjacent sequences: A124742 A124743 A124744 * A124746 A124747 A124748

Keyword

easy,sign

Author

Paul Barry, Nov 06 2006

Status

approved