A200145 Primitive (squarefree) elements of A199745.

2145, 2730, 4641, 4845, 5005, 5610, 7410, 8778, 9177, 11305, 11730, 13485, 13585, 17017, 20010, 20930, 21489, 21505, 23529, 26445, 29946, 31465, 31857, 32538, 33649, 34410, 35409, 35581, 36685, 38570, 38874, 41106, 42441, 43401, 45066, 46189, 46345, 47730, 49569

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

Filter:= proc(n) local F;
  F:= ifactors(n)[2];
  if max(seq(f[2], f=F)) > 1 or nops(F) < 4 then return false fi;
  F:= map(t -> t[1], F);
  convert(F, `+`) = 2*(max(F)+min(F));
end proc:
select(Filter, [$1..10^5]); # Robert Israel, Dec 31 2015

Mathematica

Select[Range[50000], Max@@Last/@(fi=FactorInteger[#])==1&&Plus@@(pl=First/@fi)/2==pl[[1]]+pl[[-1]]&] (*Ray Chandler, Nov 14 2011*)

Crossrefs

Intersection of A199745 and A005117.

Sequence in context: A252547 A211601 A199745 * A179271 A118576 A259413

Adjacent sequences: A200142 A200143 A200144 * A200146 A200147 A200148

Keyword

nonn

Author

Ray Chandler, Nov 14 2011

Status

approved