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A174158
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Triangle read by rows: T(n,m) = (binomial(n - 1, m - 1)*binomial(n, m - 1)/m)^2.
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4
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1, 1, 1, 1, 9, 1, 1, 36, 36, 1, 1, 100, 400, 100, 1, 1, 225, 2500, 2500, 225, 1, 1, 441, 11025, 30625, 11025, 441, 1, 1, 784, 38416, 240100, 240100, 38416, 784, 1, 1, 1296, 112896, 1382976, 3111696, 1382976, 112896, 1296, 1, 1, 2025, 291600, 6350400, 28005264, 28005264, 6350400, 291600, 2025, 1
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OFFSET
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1,5
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LINKS
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FORMULA
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T(n,m) = (binomial(n - 1, m - 1)*binomial(n, m - 1)/m)^2.
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EXAMPLE
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n\m | 1 2 3 4 5 6 7
----|--------------------------------------------------------------
1 | 1
2 | 1 1
3 | 1 9 1
4 | 1 36 36 1
5 | 1 100 400 100 1
6 | 1 225 2500 2500 225 1
7 | 1 441 11025 30625 11025 441 1
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MAPLE
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a := (n, m) -> binomial(n-1, m-1)^2*binomial(n, m-1)^2/m^2: seq(seq(a(n, m), m = 1 .. n), n = 1 .. 10) # Stefano Spezia, Dec 23 2018
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MATHEMATICA
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T[n_, m_] = (Binomial[n - 1, m - 1]*Binomial[n, m - 1]/m)^2; Flatten[Table[Table[t[n, m], {m, 1, n}], {n, 1, 10}]]
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PROG
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(GAP) Flat(List([1..10], n->List([1..n], m->(Binomial(n-1, m-1)*Binomial(n, m-1)/m)^2))); # Stefano Spezia, Dec 23 2018
(PARI)
T(n, m)= (binomial(n-1, m-1)*binomial(n, m-1)/m)^2;
tabl(nn) = for(n=1, nn, for(m=1, n, print1(T(n, m), ", ")); print);
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CROSSREFS
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KEYWORD
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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