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 A351411 #13 Oct 01 2023 07:24:15
%S A351411 1,2,2,2,2,4,2,3,3,4,2,5,2,4,4,4,2,6,2,5,4,4,2,7,3,4,3,5,2,8,2,5,4,4,
%T A351411 4,8,2,4,4,7,2,8,2,5,6,4,2,9,3,6,4,5,2,7,4,7,4,4,2,11,2,4,6,6,4,8,2,5,
%U A351411 4,8,2,11,2,4,6,5,4,8,2,9,4,4,2,11,4,4,4,7,2,12,4,5,4
%N A351411 Number of divisors of n not of the form p^p, p prime.
%H A351411 Amiram Eldar, <a href="/A351411/b351411.txt">Table of n, a(n) for n = 1..10000</a>
%F A351411 a(n) = tau(n) - Sum_{d|n} [rad(d) = Omega(d)*[omega(d) = 1]], where [ ] is the Iverson bracket.
%F A351411 a(n) = A000005(n) - A129251(n).
%F A351411 Sum_{k=1..n} a(k) ~ n * (log(n) + c), where c = A147533 - A094289 = -0.1329269215... . _Amiram Eldar_, Oct 01 2023
%e A351411 a(108) = 10; 2 of the 12 divisors of 108 are of the form p^p (p prime), namely 4 = 2^2 and 27 = 3^3; therefore a(108) = 12-2 = 10.
%t A351411 f1[p_, e_] := e + 1; f2[p_, e_] := If[e < p, 0, 1]; a[1] = 1; a[n_] := Times @@ f1 @@@ (f = FactorInteger[n]) - Plus @@ f2 @@@ f; Array[a, 100] (* _Amiram Eldar_, Oct 01 2023 *)
%o A351411 (PARI) a(n) = {my(f = factor(n)); vecprod(apply(x -> x+1, f[, 2])) - sum(i = 1, #f~, f[i, 2] >= f[i, 1]); } \\ _Amiram Eldar_, Oct 01 2023
%Y A351411 Cf. A000005 (tau), A001221 (omega), A001222 (Omega), A007947 (rad).
%Y A351411 Cf. A051674, A129251.
%K A351411 nonn,easy
%O A351411 1,2
%A A351411 _Wesley Ivan Hurt_, Feb 10 2022