A322352 a(n) = max(A003557(n), A173557(n)).

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

Antti Karttunen, Table of n, a(n) for n = 1..16384

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));

Crossrefs

Cf. A000010, A003557, A173557, A322320, A322321, A322351, A322355.

Sequence in context: A090624 A304407 A099735 * A091279 A096002 A082175

Adjacent sequences: A322349 A322350 A322351 * A322353 A322354 A322355

Keyword

nonn

Author

Antti Karttunen, Dec 05 2018

Status

approved