This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A132751 #5 Feb 16 2021 17:48:41 %S A132751 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 A132751 279,209,83,13,15,111,335,559,559,335,111,15,17,143,503,1007,1259, %U A132751 1007,503,143,17,19,179,719,1679,2519,2519,1679,719,179,19 %N A132751 Triangle T(n, k) = 2/Beta(n-k+1, k) - 1, read by rows. %H A132751 G. C. Greubel, <a href="/A132751/b132751.txt">Rows n = 1..100 of the triangle, flattened</a> %F A132751 T(n, k) = 2*A003506(n, k) - 1, an infinite lower triangular matrix. %F A132751 From _G. C. Greubel_, Feb 16 2021: (Start) %F A132751 T(n, k) = 2/Beta(n-k+1, k) - 1. %F A132751 Sum_{k=1..n} T(n, k) = n*(2^n -1) = A066524(n). (End) %e A132751 First few rows of the triangle are: %e A132751 1; %e A132751 3, 3; %e A132751 5, 11, 5; %e A132751 7, 23, 23, 7; %e A132751 9, 39, 59, 39, 9; %e A132751 11, 59, 119, 119, 59, 11; %e A132751 13, 83, 209, 279, 209, 83, 13; %e A132751 15, 111, 335, 559, 559, 335, 111, 15; %e A132751 ... %t A132751 T[n_, k_]:= 2/Beta[n-k+1, k] - 1; %t A132751 Table[T[n, k], {n,12}, {k,n}]//Flatten (* _G. C. Greubel_, Feb 16 2021 *) %o A132751 (Sage) %o A132751 def A132751(n, k): return 2/beta(n-k+1, k) - 1 %o A132751 flatten([[A132751(n,k) for k in (1..n)] for n in (1..12)]) # _G. C. Greubel_, Feb 16 2021 %o A132751 (Magma) %o A132751 A132751:= func< n,k | 2*Factorial(n)/(Factorial(k-1)*Factorial(n-k)) -1 >; %o A132751 [A132751(n, k): k in [1..n], n in [1..12]]; // _G. C. Greubel_, Feb 16 2021 %Y A132751 Cf. A003506, A066524. %K A132751 nonn,tabl %O A132751 1,2 %A A132751 _Gary W. Adamson_, Aug 28 2007