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A111527 Inverse of A111526. Row sums have general term C(n,floor(n/2))*(cos(Pi*n/2) + sin(Pi*n/2)). 1
1, 0, 1, -3, 0, 1, 0, -4, 0, 1, 10, 0, -5, 0, 1, 0, 15, 0, -6, 0, 1, -35, 0, 21, 0, -7, 0, 1, 0, -56, 0, 28, 0, -8, 0, 1, 126, 0, -84, 0, 36, 0, -9, 0, 1, 0, 210, 0, -120, 0, 45, 0, -10, 0, 1, -462, 0, 330, 0, -165, 0, 55, 0, -11, 0, 1, 0, -792, 0, 495, 0, -220, 0, 66, 0, -12, 0, 1, 1716, 0, -1287, 0, 715, 0, -286, 0, 78, 0, -13, 0, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,4
COMMENTS
Inverse of a scaled Chebyshev triangle.
LINKS
FORMULA
Riordan array (c^2(-x^2)(1+x^2c(-x^2))/sqrt(1+4x^2), x*c(-x^2)), c(x) the g.f. of A000108.
EXAMPLE
Triangle begins
1;
0, 1;
-3, 0, 1;
0, -4, 0, 1;
10, 0, -5, 0, 1;
0, 15, 0, -6, 0, 1;
-35, 0, 21, 0, -7, 0, 1;
CROSSREFS
Sequence in context: A117179 A111526 A117178 * A035695 A100257 A318315
KEYWORD
easy,sign,tabl
AUTHOR
Paul Barry, Aug 05 2005
STATUS
approved

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Last modified March 19 04:58 EDT 2024. Contains 370952 sequences. (Running on oeis4.)