This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A066238 #12 Sep 26 2019 09:05:23 %S A066238 2,12,18,40,56,304,550,748,1504,3230,3770,6976,29824,124672,351351, %T A066238 382772,510464,537248,698528,791264,1081568,1279136,2065408,2279072, %U A066238 211855016,561841408,731378944,3365232128,3557004544 %N A066238 The floor(n/3)-perfect numbers, where f-perfect numbers for an arithmetical function f are defined in A066218. %C A066238 It appears that there are more floor(n/N)-perfect numbers the larger N is. (Here N = 3.) %H A066238 J. Pe, <a href="http://jlpe.tripod.com/gpn/fperfect.htm">On a Generalization of Perfect Numbers</a>, J. Rec. Math., 31(3) (2002-2003), 168-172. %e A066238 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. %t A066238 f[x_] := Floor[x/3]; Select[ Range[2, 10^5], 2 * f[ # ] == Apply[ Plus, Map[ f, Divisors[ # ] ] ] & ] %Y A066238 Cf. A066218. %K A066238 nonn,more %O A066238 1,1 %A A066238 _Joseph L. Pe_, Dec 19 2001 %E A066238 a(14)-a(29) from _Amiram Eldar_, Sep 26 2019