

A066238


The floor(n/3)perfect numbers, where fperfect numbers for an arithmetical function f are defined in A066218.


0



2, 12, 18, 40, 56, 304, 550, 748, 1504, 3230, 3770, 6976, 29824
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OFFSET

1,1


COMMENTS

It appears that there are more floor(n/N)perfect numbers the larger N is. (Here N = 3.)


LINKS

Table of n, a(n) for n=1..13.
J. Pe, On a Generalization of Perfect Numbers, J. Rec. Math., 31(3) (20022003), 168172.


EXAMPLE

Let f(n) = floor(n/3). Then f(12) = 6 = 3+2+1+0 = f(6)+f(4)+f(3)+f(1); so 12 is a term of the sequence.


MATHEMATICA

f[x_] := Floor[x/3]; Select[ Range[2, 10^5], 2 * f[ # ] == Apply[ Plus, Map[ f, Divisors[ # ] ] ] & ]


CROSSREFS

Sequence in context: A281353 A257256 A190044 * A101074 A115109 A048001
Adjacent sequences: A066235 A066236 A066237 * A066239 A066240 A066241


KEYWORD

nonn


AUTHOR

Joseph L. Pe, Dec 19 2001


STATUS

approved



