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

1,2

Links

Table of n, a(n) for n=1..56.

Example

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.

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

Crossrefs

Cf. A141406.

Sequence in context: A029747 A095381 A233205 * A141341 A238110 A211385

Adjacent sequences: A158289 A158290 A158291 * A158293 A158294 A158295

Keyword

nonn

Author

J. Lowell, Mar 15 2009

Extensions

More terms from R. J. Mathar, Mar 30 2009

Status

approved