

A172291


Numbers whose square divide 2^10921.


2




OFFSET

1,1


COMMENTS

Up to now there exist only two primes p such that p^2 divide 2^(p1)1 (these two are Wieferich primes, see A001220).


LINKS

Table of n, a(n) for n=1..4.


EXAMPLE

Contribution from Reinhard Zumkeller, May 14 2010: (Start)
a(1)^2 = 9 = A177855(5);
a(2)^2 = 49 = A177855(14);
a(3)^2 = 169 = A177855(30);
a(4)^2 = 1194649 = A177855(1843). (End)


CROSSREFS

Cf. A001220, A172290, A172292, A172293.
Sequence in context: A154821 A084741 A135623 * A089305 A112618 A058027
Adjacent sequences: A172288 A172289 A172290 * A172292 A172293 A172294


KEYWORD

fini,nonn,full


AUTHOR

Artur Jasinski, Jan 30 2010


EXTENSIONS

Keyword full added by Reinhard Zumkeller, May 14 2010


STATUS

approved



