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A087966
a(n) = gcd(-1 + 2^n, n^2).
4
1, 1, 1, 1, 1, 9, 1, 1, 1, 1, 1, 9, 1, 1, 1, 1, 1, 27, 1, 25, 49, 1, 1, 9, 1, 1, 1, 1, 1, 9, 1, 1, 1, 1, 1, 27, 1, 1, 1, 25, 1, 441, 1, 1, 1, 1, 1, 9, 1, 1, 1, 1, 1, 81, 1, 1, 1, 1, 1, 225, 1, 1, 49, 1, 1, 9, 1, 1, 1, 1, 1, 27, 1, 1, 1, 1, 1, 9, 1, 25, 1, 1, 1, 441, 1, 1, 1, 1, 1, 27, 1, 1, 1, 1, 1, 9, 1, 1
OFFSET
1,6
LINKS
EXAMPLE
a(6) = gcd(2^6 - 1,6^2) = gcd(64-1,36) = 9.
MAPLE
seq(gcd(2^n-1, n^2), n=1..120); # Muniru A Asiru, Sep 22 2018
PROG
(PARI) A087966(n) = gcd((2^n)-1, n^2); \\ Antti Karttunen, Sep 22 2018
(GAP) List([1..120], n->Gcd(2^n-1, n^2)); # Muniru A Asiru, Sep 22 2018
CROSSREFS
Sequence in context: A366904 A284099 A176410 * A087968 A340365 A110483
KEYWORD
nonn
AUTHOR
Labos Elemer, Sep 22 2003
STATUS
approved