OFFSET
0,10
LINKS
Peter Luschny, The P-transform.
FORMULA
Let r_n(x) = ((2*n)! / (2-2^(2*n))) * Sum_{p in P_n} (-x)^(p_1) * binomial(p_1, p_2) * binomial(p_2, p_3) * ... * binomial(p_{n-1}, p_{n}) * (2*3)^(-p_1) * (4*5)^(-p_2) * ... * (2*n*(2*n+1))^(-p_n), where P_n are the partitions of n and we say that p is a partition of n if and only if p = (p_{1}, ..., p_{n}), the p_{i} are integers, Sum_{1<=i<=n} p_i = n and p_{1} >= p_{2} >= ... >= p_{n} >= 0.
T(n, k) = numerator([x^k] r_n(x)).
EXAMPLE
The rational triangle R(n, k) begins:
[0] 1;
[1] 0, 1/6;
[2] 0, 1/70, -1/21;
[3] 0, 1/434, -1/31, 5/93;
[4] 0, 1/2286, -41/1905, 14/127, -140/1143;
[5] 0, 1/11242, -23/1533, 93/511, -40/73, 100/219;
[6] 0, 1/53222, -157/14329, 2948/10235, -3652/2047, 7700/2047, -15400/6141;
.
MAPLE
# Using function PTrans from A269941.
R_row := n -> seq(coeffs(p), p in PTrans(n, n -> 1/((2*n)*(2*n + 1)),
n -> (2*n)!/(2-2^(2*n)))): seq(seq(numer(r), r in R_row(n)), n = 0..8);
CROSSREFS
KEYWORD
AUTHOR
Peter Luschny, Sep 02 2022
STATUS
approved