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Triangle T(n, k) = 2/Beta(n-k+1, k) - 1, read by rows.
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%I #5 Feb 16 2021 17:48:41

%S 1,3,3,5,11,5,7,23,23,7,9,39,59,39,9,11,59,119,119,59,11,13,83,209,

%T 279,209,83,13,15,111,335,559,559,335,111,15,17,143,503,1007,1259,

%U 1007,503,143,17,19,179,719,1679,2519,2519,1679,719,179,19

%N Triangle T(n, k) = 2/Beta(n-k+1, k) - 1, read by rows.

%H G. C. Greubel, <a href="/A132751/b132751.txt">Rows n = 1..100 of the triangle, flattened</a>

%F T(n, k) = 2*A003506(n, k) - 1, an infinite lower triangular matrix.

%F From _G. C. Greubel_, Feb 16 2021: (Start)

%F T(n, k) = 2/Beta(n-k+1, k) - 1.

%F Sum_{k=1..n} T(n, k) = n*(2^n -1) = A066524(n). (End)

%e First few rows of the triangle are:

%e 1;

%e 3, 3;

%e 5, 11, 5;

%e 7, 23, 23, 7;

%e 9, 39, 59, 39, 9;

%e 11, 59, 119, 119, 59, 11;

%e 13, 83, 209, 279, 209, 83, 13;

%e 15, 111, 335, 559, 559, 335, 111, 15;

%e ...

%t T[n_, k_]:= 2/Beta[n-k+1, k] - 1;

%t Table[T[n, k], {n,12}, {k,n}]//Flatten (* _G. C. Greubel_, Feb 16 2021 *)

%o (Sage)

%o def A132751(n, k): return 2/beta(n-k+1, k) - 1

%o flatten([[A132751(n,k) for k in (1..n)] for n in (1..12)]) # _G. C. Greubel_, Feb 16 2021

%o (Magma)

%o A132751:= func< n,k | 2*Factorial(n)/(Factorial(k-1)*Factorial(n-k)) -1 >;

%o [A132751(n, k): k in [1..n], n in [1..12]]; // _G. C. Greubel_, Feb 16 2021

%Y Cf. A003506, A066524.

%K nonn,tabl

%O 1,2

%A _Gary W. Adamson_, Aug 28 2007