A036346 Composites n such that A001414(n) is odd and divides n.

27, 105, 150, 180, 231, 588, 627, 650, 805, 840, 897, 945, 1008, 1100, 1122, 1134, 1581, 1755, 2079, 2106, 2625, 2660, 2800, 2958, 2964, 2967, 2970, 3055, 3125, 3150, 3432, 3564, 3750, 3861, 4000, 4070, 4185, 4500, 4543, 4760, 4800, 5292, 5304, 5355

Offset

1,1

Links

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

Example

5445 = 3*3*5*11*11 -> sum = 3+3+5+11+11 = 33 (=odd) so 33 divides 5445 exactly.

Maple

filter:= proc(n) local F, s;
  if isprime(n) then return false fi;
  F:=  ifactors(n)[2];
  s:= add(t[1]*t[2], t=F);
  s::odd and ( n mod s = 0)
end proc:
select(filter, [$1..10000]); # Robert Israel, Jul 15 2020

Mathematica

With[{s = Map[{#, Total[Times @@@ FactorInteger[#]]} &, Select[Range[4, 6000], CompositeQ]]}, Select[s, Mod[#1, #2] == 0 && OddQ[#2] & @@ # &][[All, 1]] ] (* Michael De Vlieger, Jul 15 2020 *)

Crossrefs

Cf. A001414, A046346, A036345.

Sequence in context: A154377 A232283 A036923 * A140376 A046347 A158549

Adjacent sequences: A036343 A036344 A036345 * A036347 A036348 A036349

Keyword

nonn

Author

Patrick De Geest, Dec 15 1998

Extensions

Name and offset corrected by Robert Israel, Jul 15 2020

Status

approved