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 A371415 #8 Mar 22 2024 17:23:23
%S A371415 1,12,36,48,150,192,432,324,392,768,1728,1800,1452,3888,3072,2916,
%T A371415 2366,4704,3750,5400,6912,7200,5202,7220,15552,12288,14112,17424,
%U A371415 18816,12696,27648,28800,19208,34992,28392,26244,25230,45000,64800,30752,48600,62208,49152
%N A371415 Dedekind psi function applied to the cubefull exponentially odd numbers (A335988).
%H A371415 Amiram Eldar, <a href="/A371415/b371415.txt">Table of n, a(n) for n = 1..10000</a>
%F A371415 a(n) = A001615(A335988(n)).
%F A371415 Sum_{n>=1} 1/a(n) = (Pi^4/36) * Product_{p prime} (1 - (2*p-1)/p^3) = A098198 * A065464 = 1.158760974549073218921828... .
%t A371415 psi[n_] := n * Times @@ (1 + 1/FactorInteger[n][[;; , 1]]); psi[1] = 1; Join[{1}, psi /@ Select[Range[40000], AllTrue[Last /@ FactorInteger[#], #1 > 1 && OddQ[#1] &] &]]
%o A371415 (PARI) dedpsi(f) = prod(i = 1, #f~, (f[i, 1] + 1) * f[i, 1]^(f[i, 2]-1));
%o A371415 lista(max) = {my(f, ans); print1(1, ", "); for(k = 2, max, f = factor(k); ans = 1; for (i = 1, #f~, if (f[i, 2] == 1 || !(f[i, 2] % 2), ans = 0; break)); if(ans, print1(dedpsi(f), ", ")));}
%Y A371415 Cf. A001615, A065464, A098198, A335988.
%Y A371415 Similar sequences: A323332, A371413, A371414.
%K A371415 nonn,easy
%O A371415 1,2
%A A371415 _Amiram Eldar_, Mar 22 2024