login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

a(n) is the positive integer such that psi(A355045(n)) = rad(A355045(n))^a(n), where psi(k) = A001615(k) and rad(k) = A007947(k).
1

%I #11 Aug 06 2022 08:28:34

%S 2,2,3,5,4,6,3,5,5,4,7,6,6,6,6,4,5,8,5,5,7,7,7,4,6,4,9,4,6,6,9,6,6,8,

%T 4,8,8,8,8,5,5,7,8,7,5,6,5,10,7,7,7,7,5,7,7,7,5,7,9,7,7,6,9,9,9,5,9,7,

%U 6,7,6,6,9,6,7,9,8,7,6,8,8,6,6,11,8,8

%N a(n) is the positive integer such that psi(A355045(n)) = rad(A355045(n))^a(n), where psi(k) = A001615(k) and rad(k) = A007947(k).

%H Vladislav Shubin, <a href="/A355059/b355059.txt">Table of n, a(n) for n = 1..1000</a>

%t DedekindPsi[n_] := n * Product[(1 + 1/i), {i, FactorInteger[n][[All, 1]]}];

%t bound = 86

%t For[s = 1, s <= bound, s++,

%t If[s == 1, Print["m = ", 1]; s = s + 1;];

%t Q = Prime[s];

%t InitialArray = FactorInteger[If[Q != 3, 3*(Q + 1), 2]];

%t For[i = 1, i <= Length[InitialArray] - 1, i++,

%t CurrentArray = FactorInteger[InitialArray[[-i, 1]] + 1] ~Join~ InitialArray;

%t InitialArray = FactorInteger[Product[CurrentArray[[k, 1]] ^ CurrentArray[[k, 2]], {k, 1, Length[CurrentArray]}]];

%t ];

%t InitialArray = InitialArray~Join~{{Q, 0}};

%t m = Max[InitialArray[[All, 2]]];

%t If[Q == 3, m = m + 1];

%t Print["m = ", m]

%t ];

%Y Cf. A001615, A007947, A355045.

%K nonn

%O 1,1

%A _Vladislav Shubin_, Jun 16 2022