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 A158193 Irregular triangle T(n, k) = ((-1)^(k+1)/2)*Sum_{j=0..n-2*k} binomial(n+2, j)*binomial(n+2, j+k+1)* binomial(n+2, j+2*k+2), read by rows. 1
 -1, -9, -72, 3, -550, 50, -4140, 585, -10, -31017, 5880, -245, -232288, 54488, -3808, 35, -1742148, 480816, -47880, 1134, -13095450, 4110750, -532350, 22050, -126, -98687600, 34397880, -5466780, 333960, -5082, -745652160, 283510260, -53143200, 4348377, -118800, 462 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS G. C. Greubel, Rows n = 0..100 of the irregular triangle, flattened Matjaz Konvalinka, An inverse matrix formula in the right-quantum algebra, Electron. J. Combin. 15 (2008), R23. FORMULA T(n, k) = ((-1)^(k+1)/2)*Sum_{j=0..n-2*k} binomial(n+2, j)*binomial(n+2, j+k+1)* binomial(n+2, j+2*k+2). EXAMPLE Irregular triangle begins as:           -1;           -9;          -72,         3;         -550,        50;        -4140,       585,       -10;       -31017,      5880,      -245;      -232288,     54488,     -3808,      35;     -1742148,    480816,    -47880,    1134;    -13095450,   4110750,   -532350,   22050,    -126;    -98687600,  34397880,  -5466780,  333960,   -5082;   -745652160, 283510260, -53143200, 4348377, -118800, 462; MATHEMATICA Table[Sum[(-1)^(k+1)*Binomial[n+2, j]*Binomial[n+2, j+k+1]*Binomial[n+2, j+2*k+2], {j, 0, n-2*k}]/2, {n, 0, 10}, {k, 0, Floor[n/2]}]//Flatten PROG (MAGMA) A158193:= func< n, k | ((-1)^(k+1)/2)*(&+[Binomial(n+2, j)*Binomial(n+2, j+k+1)*Binomial(n+2, j+2*k+2): j in [0..n-2*k]]) >; [A158193(n, k): k in [0..Floor(n/2)], n in [0..12]]; // G. C. Greubel, Jun 26 2021 (Sage) def A158193(n, k): return ((-1)^(k+1)/2)*sum( binomial(n+2, j)*binomial(n+2, j+k+1)*binomial(n+2, j+2*k+2) for j in (0..n-2*k) ) flatten([[A158193(n, k) for k in (0..n//2)] for n in (0..12)]) # G. C. Greubel, Jun 26 2021 CROSSREFS Sequence in context: A251284 A324413 A144745 * A123987 A003365 A044196 Adjacent sequences:  A158190 A158191 A158192 * A158194 A158195 A158196 KEYWORD sign,tabf AUTHOR Roger L. Bagula, Mar 13 2009 EXTENSIONS Edited by G. C. Greubel, Jun 26 2021 STATUS approved

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Last modified September 25 22:18 EDT 2021. Contains 347664 sequences. (Running on oeis4.)