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 A082926 #25 Aug 10 2022 09:57:50
%S A082926 1,0,1,0,1,1,2,1,0,0,1,0,1,1,1,0,1,0,1,0,0,0,1,0,1,1,2,3,2,2,1,2,2,2,
%T A082926 2,3,2,2,2,3,2,2,1,2,3,3,2,3,4,5,5,6,5,6,6,7,7,7,6,7,6,6,7,8,8,8,7,8,
%U A082926 8,8,7,8,7,7,8,9,9,9,8,9,10,10,9,10,10,10,10,11,10,11,11,12,12,12,12,13,12
%N A082926 Difference between the number of primes equal to or less than n and (1 + the number of nonsquarefree numbers equal to or less than n).
%H A082926 Jinyuan Wang, <a href="/A082926/b082926.txt">Table of n, a(n) for n = 1..10000</a>
%F A082926 a(n) = abs(A057627(n) + 1 - A000720(n)). - _Michel Marcus_, Mar 27 2020
%t A082926 nsfQ[n_] := n == 1 || ! SquareFreeQ[n]; Abs[Accumulate[Table[If[nsfQ[n], 1, 0] - If[PrimeQ[n], 1, 0], {n, 1, 100}]]] (* _Amiram Eldar_, Jun 13 2022 *)
%o A082926 (PARI) a(n) = abs(sum(k=1, n, !issquarefree(k)) + 1 - primepi(n)); \\ _Michel Marcus_, Mar 27 2020
%Y A082926 Cf. A000720, A057627.
%K A082926 nonn
%O A082926 1,7
%A A082926 Anonymous, Apr 15 2003
%E A082926 Name edited by _Michel Marcus_, Jun 14 2022