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 A127775 #9 Feb 27 2021 13:29:02 %S A127775 1,0,3,0,0,5,0,0,0,7,0,0,0,0,9,0,0,0,0,0,11,0,0,0,0,0,0,13,0,0,0,0,0, %T A127775 0,0,15,0,0,0,0,0,0,0,0,17,0,0,0,0,0,0,0,0,0,19,0,0,0,0,0,0,0,0,0,0, %U A127775 21,0,0,0,0,0,0,0,0,0,0,0,23,0,0,0,0,0,0,0,0,0,0,0,0,25,0,0,0,0,0,0,0,0,0,0 %N A127775 Triangle read by rows: row n consists of n-1 zeros followed by 2n-1. %C A127775 a(A000217(n)) = A005408(n-1), T(n,n) = 2*n - 1. - _Reinhard Zumkeller_, Feb 11 2007 %F A127775 T(n,k) = (2*n - 1) * 0^(n - k), 1<=k<=n. - _Reinhard Zumkeller_, Feb 11 2007 %e A127775 First few rows of the triangle are: %e A127775 1; %e A127775 0, 3; %e A127775 0, 0, 5; %e A127775 0, 0, 0, 7; %e A127775 ... %Y A127775 Cf. A000217, A127648, A127773, A127774, A005408, A014480, A001787. %K A127775 nonn,tabl %O A127775 1,3 %A A127775 _Gary W. Adamson_, Jan 28 2007 %E A127775 More terms from _Reinhard Zumkeller_, Feb 11 2007