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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

COMMENTS

This and A066715 are mostly equal; for differences see A083344.

LINKS

Table of n, a(n) for n=1..105.

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

Cf. A057643, A066715, A000203, A083344.

Sequence in context: A101874 A318449 A066715 * A031178 A327401 A091407

Adjacent sequences:  A082454 A082455 A082456 * A082458 A082459 A082460

KEYWORD

nonn

AUTHOR

Labos Elemer, Apr 25 2003

STATUS

approved

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Last modified October 22 04:25 EDT 2019. Contains 328315 sequences. (Running on oeis4.)