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 A066238 The floor(n/3)-perfect numbers, where f-perfect numbers for an arithmetical function f are defined in A066218. 0
 2, 12, 18, 40, 56, 304, 550, 748, 1504, 3230, 3770, 6976, 29824 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS It appears that there are more floor(n/N)-perfect numbers the larger N is. (Here N = 3.) LINKS J. Pe, On a Generalization of Perfect Numbers, J. Rec. Math., 31(3) (2002-2003), 168-172. 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

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Last modified January 18 23:05 EST 2019. Contains 319282 sequences. (Running on oeis4.)