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A322352
a(n) = max(A003557(n), A173557(n)).
5
1, 1, 2, 2, 4, 2, 6, 4, 3, 4, 10, 2, 12, 6, 8, 8, 16, 3, 18, 4, 12, 10, 22, 4, 5, 12, 9, 6, 28, 8, 30, 16, 20, 16, 24, 6, 36, 18, 24, 4, 40, 12, 42, 10, 8, 22, 46, 8, 7, 5, 32, 12, 52, 9, 40, 6, 36, 28, 58, 8, 60, 30, 12, 32, 48, 20, 66, 16, 44, 24, 70, 12, 72, 36, 8, 18, 60, 24, 78, 8, 27, 40, 82, 12, 64, 42, 56, 10, 88, 8
OFFSET
1,3
LINKS
FORMULA
a(n) = max(A003557(n), A173557(n)).
a(n) = A000010(n) / A322351(n).
MATHEMATICA
a[n_] := If[n == 1, 1, Module[{f=FactorInteger[n]}, Max[ Times @@ (First[#]^ (Last[#]-1)& /@ f), Times@@((#-1)& @@@ f)]]]; Array[a, 120] (* Amiram Eldar, Dec 05 2018 *)
PROG
(PARI)
A003557(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 2] = f[i, 2]-1); factorback(f); }; \\ From A003557
A173557(n) = factorback(apply(p -> p-1, factor(n)[, 1]));
A322352(n) = max(A003557(n), A173557(n));
KEYWORD
nonn
AUTHOR
Antti Karttunen, Dec 05 2018
STATUS
approved