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A205813
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Triangle T(n,k), read by rows, given by (0, 2, 1, 1, 1, 1, 1, 1, 1, ...) DELTA (1, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938.
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3
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1, 0, 1, 0, 2, 1, 0, 6, 4, 1, 0, 20, 16, 6, 1, 0, 70, 64, 30, 8, 1, 0, 252, 256, 140, 48, 10, 1, 0, 924, 1024, 630, 256, 70, 12, 1, 0, 3432, 4096, 2772, 1280, 420, 96, 14, 1, 0, 12870, 16384, 12012, 6144, 2310, 640, 126, 16, 1
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OFFSET
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0,5
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COMMENTS
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Riordan array (1, x/sqrt(1-4x)). Inverse of Riordan array (1, x*exp(arcsinh(-2x)).
T is the convolution triangle of the shifted central binomial coefficients binomial(2*(n-1), n-1). - Peter Luschny, Oct 19 2022
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LINKS
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FORMULA
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G.f.: sqrt(1-4x)/(sqrt(1-4x)-y*x).
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EXAMPLE
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Triangle begins:
1;
0, 1;
0, 2, 1;
0, 6, 4, 1;
0, 20, 16, 6, 1;
0, 70, 64, 30, 8, 1;
0, 252, 256, 140, 48, 10, 1;
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MAPLE
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# Uses function PMatrix from A357368.
PMatrix(10, n -> binomial(2*(n-1), n-1)); # Peter Luschny, Oct 19 2022
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CROSSREFS
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Cf. A054335 and columns listed there.
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KEYWORD
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AUTHOR
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STATUS
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approved
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