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 A287763 #36 Jun 23 2017 19:12:42
%S A287763 25,27,32,49,54,64,81,96,98,121,125,128,135,147,162,169,189,192,216,
%T A287763 224,242,243,245,250,256,289,297,320,338,343,351,352,361,363,375,384,
%U A287763 392,405,416,432,448,486,500,507,512,513,529,539,567,576,578,605,621,625,637,640,648,675,686,704,722,729,736,750,768,775,783,784
%N A287763 Numbers n for which A230625(n) < n, where A230625 is the concatenation of the prime factorization written in binary, converted back to decimal.
%C A287763 Relevant for the study of closed orbits. (This is to A230625 the analog of A195330 for A080670.) Up to a certain limit, the trajectory of all numbers, under iteration of A230625, end either in a prime (fixed point) or in one of the orbits {1007, 1269} or {1503,3751}.
%C A287763 See A288985 for the analog when A287874 is used instead of A230625, i.e., without converting back the concatenation of the binary strings to decimal, or rather, reading it as a decimal number.
%t A287763 Select[Range@ 800, Function[n, FromDigits[#, 2] < n &@ Flatten@ Map[IntegerDigits[#, 2] &, FactorInteger[n] /. {p_, 1} :> {p}]]] (* _Michael De Vlieger_, Jun 23 2017 *)
%o A287763 (PARI) forcomposite(n=1,1e6,A230625(n)<n&&print1(n","))
%Y A287763 Cf. A230625, A195330, A080670, A287874.
%K A287763 nonn,base
%O A287763 1,1
%A A287763 _M. F. Hasler_, Jun 21 2017