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 A176013 Triangle, read by rows, T(n, k) = (-1)^n * n!/(k*k!) * binomial(n-1, k-1) * binomial(n, k-1). 5
 -1, 2, 1, -6, -9, -1, 24, 72, 24, 1, -120, -600, -400, -50, -1, 720, 5400, 6000, 1500, 90, 1, -5040, -52920, -88200, -36750, -4410, -147, -1, 40320, 564480, 1317120, 823200, 164640, 10976, 224, 1, -362880, -6531840, -20321280, -17781120, -5334336, -592704, -24192, -324, -1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Row sums are: -1, 3, -16, 121, -1171, 13711, -187468, 2920961, -50948677, 981458011, ... LINKS G. C. Greubel, Rows n = 1..100 of the triangle, flattened FORMULA T(n, k) = (-1)^n * n!/(k*k!) * binomial(n-1, k-1) * binomial(n, k-1). T(n, k) = binomial(n+1, k) * A008297(n, k)/(n+1). - G. C. Greubel, Feb 08 2021 EXAMPLE Triangle begins as:        -1;         2,        1;        -6,       -9,        -1;        24,       72,        24,         1;      -120,     -600,      -400,       -50,       -1;       720,     5400,      6000,      1500,       90,       1;     -5040,   -52920,    -88200,    -36750,    -4410,    -147,     -1;     40320,   564480,   1317120,    823200,   164640,   10976,    224,    1;   -362880, -6531840, -20321280, -17781120, -5334336, -592704, -24192, -324, -1; MATHEMATICA T[n_, k_] = (-1)^n*n!/(k*k!)*Binomial[n-1, k-1]*Binomial[n, k-1]; Table[T[n, k], {n, 12}, {k, n}]//Flatten PROG (Sage) flatten([[(-1)^n*(factorial(n)/(k*factorial(k)))*binomial(n-1, k-1)*binomial(n, k-1) for k in (1..n)] for n in (1..12)]) # G. C. Greubel, Feb 08 2021 (Magma) [(-1)^n*(Factorial(n)/(k*Factorial(k)))*Binomial(n-1, k-1)*Binomial(n, k-1) : k in [1..n], n in [1..12]]; // G. C. Greubel, Feb 08 2021 CROSSREFS Cf. A008297. Sequence in context: A021465 A139526 A248927 * A263255 A145663 A276664 Adjacent sequences:  A176010 A176011 A176012 * A176014 A176015 A176016 KEYWORD sign,tabl,easy,less AUTHOR Roger L. Bagula, Apr 06 2010 EXTENSIONS Edited by G. C. Greubel, Feb 08 2021 STATUS approved

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Last modified September 20 12:05 EDT 2021. Contains 347586 sequences. (Running on oeis4.)