

A061110


a(1) = 1; a(n) = smallest number such that the concatenation a(1)a(2)...a(n) is a square.


9




OFFSET

1,2


COMMENTS

The next term is too large to include.
a(n) is at most doubly exponential in n. Is there also a double exponential lower bound?  Charles R Greathouse IV, Sep 19 2012


LINKS



EXAMPLE

a(1) = 1, a(1)a(2) = 16 = 4^2, a(1)a(2)a(3) = 169 = 13^2, 169744 = 412^2.


CROSSREFS



KEYWORD

base,nonn


AUTHOR



EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org), Jul 23 2001


STATUS

approved



