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 A085510 #21 Aug 20 2021 03:34:37
%S A085510 0,1,2,16,150,2757,56252,1843637,71277004,3592359440,197924252436,
%T A085510 14915743198773,1183551535975484,123024814715081453,
%U A085510 13742505172992983210,1747020721154054373156,240574984100927602314902
%N A085510 Permanent of the n X n matrix whose element (i,j) equals phi(|i-j|).
%H A085510 Vaclav Kotesovec, <a href="/A085510/b085510.txt">Table of n, a(n) for n = 1..35</a>
%e A085510 a(3)=2 because phi(0)=0, phi(1)=phi(2)=1 and so the matrix is [[0,1,1],[1,0,1],[1,1,0]] with permanent 2.
%p A085510 with(numtheory): with(linalg): p:=(i,j)->phi(abs(i-j)): seq(permanent(matrix(n,n,p)),n=1..16); # _Emeric Deutsch_, Dec 17 2004
%t A085510 a[n_] := Permanent[Table[EulerPhi[Abs[i-j]], {i, 1, n}, {j, 1, n}]]; Table[ an = a[n]; Print["a(", n, ") = ", an]; an, {n, 1, 17}] (* _Jean-François Alcover_, Jan 07 2016 *)
%o A085510 (PARI)
%o A085510 aph(n)={n=abs(n);if(n>0,eulerphi(n),0);}
%o A085510 a(n)=matpermanent(matrix(n,n,r,c,aph(r-c)));
%o A085510 vector(23,n,a(n)) \\ _Joerg Arndt_, Aug 15 2019
%Y A085510 Cf. A071083.
%K A085510 nonn,hard
%O A085510 1,3
%A A085510 Yuval Dekel (dekelyuval(AT)hotmail.com), Aug 19 2003
%E A085510 More terms from _Emeric Deutsch_, Dec 17 2004