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A087967
Integers m such that gcd(2^m-1, m^2) is not a square number.
3
18, 36, 72, 90, 100, 126, 144, 147, 162, 180, 198, 200, 234, 252, 288, 294, 300, 306, 324, 342, 360, 396, 400, 414, 441, 450, 468, 504, 522, 558, 576, 588, 600, 612, 630, 648, 666, 684, 700, 720, 735, 738, 774, 792, 800, 810, 828, 846, 882, 900, 936, 954
OFFSET
1,1
LINKS
EXAMPLE
For m = 18: gcd(262143, 324) = 27 is not a square number, so 18 is a term.
MATHEMATICA
Select[Range[1000], !IntegerQ[Sqrt[GCD[2^#-1, #^2]]] &]
PROG
(PARI) isok(m) = !issquare(gcd(2^m-1, m^2)); \\ Michel Marcus, Aug 27 2019
CROSSREFS
Sequence in context: A375663 A376439 A097926 * A070224 A083211 A156903
KEYWORD
nonn
AUTHOR
Labos Elemer, Sep 22 2003
STATUS
approved