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A322318 a(n) = gcd(A003557(n), A048250(n)). 5
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 3, 1, 2, 1, 1, 1, 4, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 6, 1, 1, 1, 2, 1, 1, 1, 2, 3, 1, 1, 4, 1, 1, 1, 2, 1, 3, 1, 4, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 12, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 4, 1, 3, 1, 2, 1, 1, 1, 4, 1, 1, 3, 2, 1, 1, 1, 2, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,12

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..20000

FORMULA

a(n) = gcd(A003557(n), A048250(n)).

a(n) = A001615(n) / A322319(n).

MATHEMATICA

a[n_] := If[n == 1, 1, Module[{f=FactorInteger[n]}, GCD[ 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

A048250(n) = factorback(apply(p -> p+1, factor(n)[, 1]));

A322318(n) = gcd(A048250(n), A003557(n));

CROSSREFS

Cf. A001615, A003557, A048250, A322319.

Cf. also A066086, A322320.

Sequence in context: A219093 A062760 A323163 * A014649 A326568 A279817

Adjacent sequences:  A322315 A322316 A322317 * A322319 A322320 A322321

KEYWORD

nonn

AUTHOR

Antti Karttunen, Dec 05 2018

STATUS

approved

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Last modified November 13 10:29 EST 2019. Contains 329093 sequences. (Running on oeis4.)