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 A014665 #29 Jul 06 2025 22:29:20
%S A014665 1,1,2,2,4,1,6,4,6,2,10,3,12,3,5,8,16,3,18,6,7,5,22,5,20,6,18,8,28,4,
%T A014665 30,16,12,8,18,9,36,9,14,12,40,6,42,13,17,11,46,11,42,10,19,15,52,9,
%U A014665 25,20,21,14,58,10,60,15,28,32,29,9,66,21,26,11,70,20,72,18,23,23,42,11,78,23,54
%N A014665 Number of new fractions m/n < 1, where (m,n)=1 and "new" means the value of m*n has not occurred before.
%D A014665 S. W. Golomb, personal communication, Svalbard, Norway, 7/97.
%H A014665 Andrew Howroyd, <a href="/A014665/b014665.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from T. D. Noe).
%e A014665 {1}, {1/2}, {1/3,2/3}, {1/4,3/4}, {1/5,...,4/5}, {5/6}, ...
%t A014665 a[1] = 1;
%t A014665 a[n_] := Sum[Boole[GCD[i, n] == 1 && Sum[t = i*n/d; Boole[GCD[t, d] == 1 && t < d < n], {d, Divisors[i*n]}] == 0], {i, 1, n - 1}];
%t A014665 Array[a, 100] (* _Jean-François Alcover_, Sep 05 2019, from PARI *)
%o A014665 (PARI) a(n)=if(n==1, 1, sum(i=1, n-1, gcd(i,n) == 1 && 0==sumdiv(i*n, d, my(t=i*n/d); gcd(t,d)==1 && d<n && t<d))) \\ _Andrew Howroyd_, Nov 16 2018
%Y A014665 Cf. A027435, A236309.
%K A014665 nonn
%O A014665 1,3
%A A014665 _N. J. A. Sloane_
%E A014665 Example corrected by and more terms from _Olivier Gérard_, Feb 1999