A240942 Numbers k that divide 2^k + 9.

1, 11, 121, 323, 117283, 432091, 4132384531, 15516834659, 15941429747, 98953554491, 3272831195051, 7362974489179, 26306805687881, 33869035218491, 280980898827691

Offset

1,2

Comments

No other terms below 10^15. Some larger terms: 53496121130110340001650284048539458491, 136243118444105327963550175410279542214992801356720577. - Max Alekseyev, Sep 29 2016

Links

Table of n, a(n) for n=1..15.

OEIS Wiki, 2^n mod n

Example

2^11 + 9 = 2057 is divisible by 11. Thus 11 is a term of this sequence.

Maple

select(n -> 9 + 2 &^ n mod n = 0, [$1..10^6]); # Robert Israel, Aug 04 2014

Prog

(PARI) for(n=1, 10^9, if(Mod(2, n)^n==-9, print1(n, ", "); ); );

Crossrefs

Cf. A051447, A188165, A245594, A245319, A245318, A244673.

Sequence in context: A015958 A014951 A223223 * A216131 A338784 A223392

Adjacent sequences: A240939 A240940 A240941 * A240943 A240944 A240945

Keyword

nonn,more,hard

Author

Derek Orr, Aug 04 2014

Extensions

a(7)-a(10) from Lars Blomberg, Nov 05 2014

a(11)-a(15) from Max Alekseyev, Sep 29 2016

Status

approved