

A050259


Numbers n such that 2^n == 3 (mod n).


21




OFFSET

1,2


COMMENTS

No other terms below 10^17.  Max Alekseyev, Oct 24 2016
Terms were computed: a(2) by the Lehmers, a(3) by Max Alekseyev, a(4) and a(5) by Joe K. Crump, a(?) = 63130707451134435989380140059866138830623361447484274774099906755 by P.L. Montgomery.


REFERENCES

R. Daniel Mauldin and S. M. Ulam, Mathematical problems and games. Adv. in Appl. Math. 8 (1987), pp. 281344.


LINKS

Table of n, a(n) for n=1..5.
Joe K. Crump, 2^n mod n
R. K. Guy, The Strong Law of Small Numbers, Amer. Math. Monthly 95 (1988), pp. 697712. See example 13.
Eric Weisstein's World of Mathematics, 2
OEIS Wiki, 2^n mod n


PROG

(PARI) is(n)=Mod(2, n)^n==3 \\ Charles R Greathouse IV, Jun 11 2015


CROSSREFS

Cf. A001567, A036236, A015940, A015910.
Sequence in context: A199631 A124977 A128172 * A249972 A233494 A175568
Adjacent sequences: A050256 A050257 A050258 * A050260 A050261 A050262


KEYWORD

nonn,more,hard


AUTHOR

Eric W. Weisstein


EXTENSIONS

a(1)a(5) certified by Max Alekseyev, Jan 27 2007, Apr 27 2009.


STATUS

approved



