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A082457
a(n) = gcd(1+2n, A057643(1+2n)).
3
1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 15, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 3, 1, 1, 1, 1, 1, 3, 1, 7, 1, 5, 1, 3, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 15, 1, 1, 3, 1, 5, 1, 1, 1, 9, 1, 1, 3, 1, 1, 3, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 7, 1, 1, 15, 1, 1, 1, 1, 1, 3, 1, 1
OFFSET
1,7
COMMENTS
This and A066715 are mostly equal; for differences see A083344.
EXAMPLE
n=22: 2n+1=45, A057643(45)=5520, a(22)=gcd(45,5520)=15 while A066715(45)=3.
MATHEMATICA
di[x_] := Apply[LCM, Divisors[x]+1] Table[GCD[2*w+1, di[1+2*w]], {w, 1, 2048}];
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Apr 25 2003
STATUS
approved