A049045 Domain of A049044.

1, 2, 4, 5, 7, 10, 11, 14, 17, 19, 22, 23, 31, 34, 37, 38, 41, 46, 61, 62, 71, 73, 74, 77, 82, 89, 103, 113, 122, 131, 139, 142, 146, 154, 157, 163, 167, 173, 178, 191, 193, 197, 206, 211, 226, 227, 233, 239, 251, 257, 262, 263, 278, 283, 293, 307, 313, 314, 317

Offset

1,2

Comments

Positive integers that divide some positive element of A003422.

From Robert Israel, Nov 14 2016: (Start)

Numbers n such that A013584(n) > 0.

If n is in the sequence, then so are all divisors of n. (End)

Links

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

Maple

filter:= proc(n) local t, r, m;
  r:= 1; t:= 1;
  for m from 1 do
    r:= r*m mod n;
    if r = 0 then return false fi;
    t:= t + r mod n;
    if t = 0 then return true fi;
  od;
end proc:
filter(1):= true:
select(filter, [$1..1000]); # Robert Israel, Nov 14 2016

Mathematica

okQ[n_] := Module[{t, r, m}, r = 1; t = 1; For[m = 1, True, m++, r = Mod[r*m, n]; If[r == 0, Return[False]]; t = Mod[t + r, n]; If[t == 0, Return[True]]]];
okQ[1] = True;
Select[Range[1000], okQ] (* Jean-François Alcover, Apr 10 2019, after Robert Israel *)

Crossrefs

A049044, A003422, A013584.

Complement of A275608.

Sequence in context: A014370 A095278 A155722 * A153766 A319301 A093013

Adjacent sequences: A049042 A049043 A049044 * A049046 A049047 A049048

Keyword

nonn

Author

David W. Wilson

Status

approved