|
Search: id:A095119
|
|
|
| A095119 |
|
Numbers n such that s(n) >= sigma(n), where s(n) = A095118(n) is the sum of the squares of the divisors of n which are <= sqrt(n), and sigma(n) = A000203(n) is the sum of the divisors of n. |
|
+0
2
|
|
| 1, 840, 900, 1080, 1225, 1260, 1440, 1600, 1680, 1800, 1848, 1890, 1980, 2016, 2100, 2160, 2340, 2400, 2520, 2640, 2700, 2772, 2800, 2880, 2970, 3024, 3080, 3120, 3136, 3150, 3240, 3276, 3300, 3360, 3465, 3528, 3600, 3640, 3696, 3780, 3900, 3960, 3969
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
EXAMPLE
|
840 is in the sequence because s(840) = 3070 >= 2880 = sigma(840).
|
|
MATHEMATICA
|
s[n_]:=Plus@@(Select[Divisors[n], #^2<=n&]^2); Select[Range[4000], s[ # ]>=DivisorSigma[1, # ]&]
|
|
CROSSREFS
|
Cf. A095118.
Sequence in context: A118380 A135639 A135640 this_sequence A102793 A068546 A033269
Adjacent sequences: A095116 A095117 A095118 this_sequence A095120 A095121 A095122
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Dean Hickerson (dean(AT)math.ucdavis.edu), following a suggestion of Leroy Quet (qq-quet(AT)mindspring.com), May 28 2004
|
|
|
Search completed in 0.002 seconds
|
