A158292 Numbers k where the sum of all of its divisors != sqrt(k) exceeds the sum of all the divisors of m != sqrt(m) for all m < k.
1, 2, 3, 4, 5, 6, 8, 10, 12, 18, 20, 24, 30, 36, 40, 42, 48, 60, 72, 84, 90, 96, 108, 120, 144, 156, 168, 180, 210, 216, 240, 288, 300, 336, 360, 420, 480, 504, 540, 600, 630, 660, 720, 840, 960, 1008, 1080, 1200, 1260, 1440, 1560, 1620, 1680, 1800, 1920, 1980
Offset: 1
Keywords
Examples
9 is not a term because the value for 8 is 1 + 2 + 4 + 8 = 15 but the value for 9 is 1 + 9 = 10.
Crossrefs
Cf. A141406.
Programs
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Maple
sodNosqrt := proc(n) a := 0 ; for d in numtheory[divisors](n) do if d^2 <> n then a := a+d ; fi; od: a ; end: L := [seq(sodNosqrt(n),n=1..2500)] ; read("transforms") ; RECORDS(L)[2] ; # R. J. Mathar, Mar 30 2009
Extensions
More terms from R. J. Mathar, Mar 30 2009