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 A071083 #8 Jun 27 2024 01:37:46
%S A071083 0,-1,2,-4,6,-5,-84,245,924,-8816,-78556,-58667,6779732,10484275,
%T A071083 -363899598,-6434306752,-13046891490,20608641823,1894093427008,
%U A071083 -6177545952015,18227184915788,-46023445768832,-8765268354146700,-1210879926442292743,-149657142827643535248
%N A071083 Determinant of the n X n matrix whose element (i,j) equals phi(|i-j|).
%t A071083 f[n_] := Det[ Table[ EulerPhi[ Abs[i - j]], {i, 1, n}, {j, 1, n}]]; Table[ f[n], {n, 1, 22}]
%Y A071083 Cf. A071078, A071079, A071082.
%K A071083 sign
%O A071083 1,3
%A A071083 _Robert G. Wilson v_, May 26 2002
%E A071083 More terms from _Sean A. Irvine_, Jun 27 2024