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A340074
a(n) = gcd(A003961(n)-1, A339904(n)).
2
1, 1, 1, 1, 3, 1, 5, 1, 1, 1, 3, 1, 1, 1, 1, 1, 9, 1, 11, 1, 1, 1, 7, 1, 3, 1, 1, 1, 15, 1, 9, 1, 1, 1, 1, 1, 5, 1, 1, 1, 21, 1, 23, 1, 3, 1, 13, 1, 5, 1, 1, 1, 29, 1, 9, 1, 1, 1, 15, 1, 33, 1, 1, 1, 1, 1, 35, 1, 1, 5, 9, 1, 39, 1, 1, 1, 1, 1, 41, 1, 1, 1, 11, 1, 3, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 25, 1, 3, 1, 51, 1, 53, 1, 3
OFFSET
1,5
COMMENTS
Odd part of A340071(n).
FORMULA
a(n) = gcd(A003961(n)-1, A339904(n)).
a(n) = A000265(A340071(n)).
a(n) = A339904(n) / A340075(n).
PROG
(PARI)
A000265(n) = (n>>valuation(n, 2));
A003961(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
A339904(n) = A000265(eulerphi(A003961(n)));
A340074(n) = gcd(A003961(n)-1, A339904(n));
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Dec 29 2020
STATUS
approved