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 A371413 #9 Mar 22 2024 17:22:56
%S A371413 1,12,24,36,48,96,108,150,192,432,324,384,392,864,768,750,1296,972,
%T A371413 1728,1800,1536,2592,1452,3456,3888,3600,3072,2916,2366,2744,5184,
%U A371413 4704,3750,5400,6912,7776,7200,6144,5202,9000,10368,9408,11664,8748,7220,13824,15552
%N A371413 Dedekind psi function applied to the cubefull numbers (A036966).
%H A371413 Amiram Eldar, <a href="/A371413/b371413.txt">Table of n, a(n) for n = 1..10000</a>
%F A371413 a(n) = A001615(A036966(n)).
%F A371413 Sum_{n>=1} 1/a(n) = Product_{p prime} (1 + 1/((p^2-1)*p)) = 1.231291... (A065487).
%t A371413 psi[n_] := n * Times @@ (1 + 1/FactorInteger[n][[;; , 1]]); psi[1] = 1; Join[{1}, psi /@ Select[Range[20000], AllTrue[Last /@ FactorInteger[#], #1 > 2 &] &]]
%t A371413 (* or *)
%t A371413 f[n_] := Module[{f = FactorInteger[n], p, e}, If[n == 1, 1, p = f[[;;, 1]]; e = f[[;;, 2]]; If[Min[e] > 2, Times @@ ((p+1) * p^(e-1)), Nothing]]]; Array[f, 20000]
%o A371413 (PARI) dedpsi(f) = prod(i = 1, #f~, (f[i, 1] + 1) * f[i, 1]^(f[i, 2]-1));
%o A371413 lista(max) = {my(f); print1(1, ", "); for(k = 2, max, f = factor(k); if(vecmin(f[, 2]) > 2, print1(dedpsi(f), ", "))); }
%Y A371413 Cf. A001615, A036966, A065464.
%Y A371413 Similar sequences: A323332, A371412, A371415.
%K A371413 nonn,easy
%O A371413 1,2
%A A371413 _Amiram Eldar_, Mar 22 2024