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A177457
Triangle read by rows; union of A007318 and A112467.
1
0, 1, 1, -1, 1, 1, 0, 1, -1, 1, 1, 1, 2, -1, 1, -1, 1, 1, 2, 3, 0, 3, -2, 1, -1, 1, 1, 3, 4, 2, 6, -2, 4, -3, 1, -1, 1, 1, 4, 5, 5, 10, 0, 10, -5, 5, -4, 1, -1, 1, 1, 5, 6, 9, 15, 5, 20, -5, 15, -9, 6, -5, 1, -1, 1, 1, 6, 7, 14, 21, 14, 35, 0, 35, -14, 21, -14, 7, -6, 1, -1, 1, 1, 7, 8, 20, 28
OFFSET
1,13
FORMULA
T(n, k) = T(n-1, k-1) + T(n-1, k+1), for n > 2 and T(n, k) = 0 for negative k or k > 2*n-1. - Thomas Scheuerle, Feb 02 2023
EXAMPLE
Triangle begins:
0
1 1 -1
1 1 0 1 -1
1 1 1 2 -1 1 -1
1 1 2 3 0 3 -2 1 -1
1 1 3 4 2 6 -2 4 -3 1 -1
PROG
(MATLAB)
function a = A177457( max_row )
a = [0 1 1 -1];
for n = 3:max_row
r = [0 0 a(end-((n-2)*2):end) 0 0];
a = [a r(1:end-2)+r(3:end)];
end
end % Thomas Scheuerle, Feb 02 2023
CROSSREFS
Sequence in context: A283530 A326753 A062093 * A373125 A357139 A046214
KEYWORD
tabf,sign
AUTHOR
Mark Dols, May 09 2010
EXTENSIONS
More terms from Thomas Scheuerle, Feb 02 2023
STATUS
approved