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A322351
a(n) = min(A003557(n), A173557(n)).
5
1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 4, 1, 2, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 4, 1, 1, 1, 2, 3, 1, 1, 2, 6, 4, 1, 2, 1, 2, 1, 4, 1, 1, 1, 2, 1, 1, 3, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 5, 2, 1, 1, 1, 4, 2, 1, 1, 2, 1, 1, 1, 4, 1, 3, 1, 2, 1, 1, 1, 2, 1, 6, 3, 4, 1, 1, 1, 4, 1
OFFSET
1,9
LINKS
FORMULA
a(n) = min(A003557(n), A173557(n)).
a(n) = A000010(n) / A322352(n).
MATHEMATICA
a[n_] := If[n == 1, 1, Module[{f=FactorInteger[n]}, Min[ 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]));
A322351(n) = min(A003557(n), A173557(n));
KEYWORD
nonn
AUTHOR
Antti Karttunen, Dec 05 2018
STATUS
approved