A087967 Integers m such that gcd(2^m-1, m^2) is not a square number.
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
Keywords
Examples
For m = 18: gcd(262143, 324) = 27 is not a square number, so 18 is a term.
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000
Programs
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Mathematica
Select[Range[1000], !IntegerQ[Sqrt[GCD[2^#-1, #^2]]] &]
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PARI
isok(m) = !issquare(gcd(2^m-1, m^2)); \\ Michel Marcus, Aug 27 2019