%I #10 Sep 08 2022 08:46:05
%S -3,-5,-1,-9,-5,-3,-17,-3,-5,-1,-33,-17,-9,-1,-3,-65,-11,-17,-3,-5,-1,
%T -129,-65,-33,-17,-9,-5,-3,-257,-43,-65,-11,-17,-1,-5,-1,-513,-257,
%U -129,-13,-33,-17,-9,-1,-3,-1025,-171,-257,-43,-65,-11,-17,-3,-5,-1
%N Triangle T(n,k), read by rows: T(n,k) is the numerator of (1+2^(n-k+1))/(1-2^(k+1)).
%C The denominators are given in A228147.
%H Vincenzo Librandi, <a href="/A228146/b228146.txt">Rows n = 0..90, flattened</a>
%e Triangle begins:
%e -3;
%e -5, -1;
%e -9, -5, -3;
%e -17, -3, -5, -1;
%e -33, -17, -9, -1, -3;
%e -65, -11, -17, -3, -5, -1;
%e -129, -65, -33, -17, -9, -5, -3;
%e -257, -43, -65, -11, -17, -1, -5, -1;
%e -513, -257, -129, -13, -33, -17, -9, -1, -3;
%e -1025, -171, -257, -43, -65, -11, -17, -3, -5, -1; etc.
%t a[n_, k_] := Numerator[(1 + 2^(n - k + 1))/(1 - 2^(k + 1))]; Table[a[n, k], {n, 0, 10}, {k, 0, n}] // Flatten
%o (Magma) [Numerator((1+2^(n-k+1))/(1-2^(k+1))): k in [0..n], n in [0..10]];
%Y Cf. A228147.
%K sign,tabl
%O 0,1
%A _Vincenzo Librandi_, Aug 15 2013