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A322020
a(n) = Product_{d|n, gcd(d,n/d) is a prime power} gcd(d,n/d).
2
1, 1, 1, 2, 1, 1, 1, 4, 3, 1, 1, 4, 1, 1, 1, 16, 1, 9, 1, 4, 1, 1, 1, 16, 5, 1, 9, 4, 1, 1, 1, 64, 1, 1, 1, 36, 1, 1, 1, 16, 1, 1, 1, 4, 9, 1, 1, 256, 7, 25, 1, 4, 1, 81, 1, 16, 1, 1, 1, 16, 1, 1, 9, 512, 1, 1, 1, 4, 1, 1, 1, 144, 1, 1, 25, 4, 1, 1, 1, 256, 81, 1, 1, 16, 1, 1, 1, 16, 1, 81, 1, 4, 1, 1, 1, 4096, 1, 49, 9, 100, 1, 1, 1, 16, 1
OFFSET
1,4
LINKS
FORMULA
a(n) = Product_{d|n} gcd(d,n/d)^A069513(gcd(d,n/d)).
PROG
(PARI) A322020(n) = { my(m=1, p); fordiv(n, d, p = gcd(d, n/d); if(isprimepower(p), m *= p)); m; };
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 28 2018
STATUS
approved