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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.
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%I #6 Feb 01 2019 20:05:22

%S 1,2,3,4,5,6,8,10,12,18,20,24,30,36,40,42,48,60,72,84,90,96,108,120,

%T 144,156,168,180,210,216,240,288,300,336,360,420,480,504,540,600,630,

%U 660,720,840,960,1008,1080,1200,1260,1440,1560,1620,1680,1800,1920,1980

%N 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.

%e 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.

%p 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

%Y Cf. A141406.

%K nonn

%O 1,2

%A _J. Lowell_, Mar 15 2009

%E More terms from _R. J. Mathar_, Mar 30 2009