OFFSET
0,4
COMMENTS
a(n) <= n!-1, because with k=n!-1 we have n!+k^2+k = n! + (n!)^2 - 2*n! + 1 + n! - 1 = (n!)^2, a perfect square.
LINKS
Jon E. Schoenfield, Table of n, a(n) for n = 0..42
EXAMPLE
4! + 3^2+3 = 24+12 = 36, a perfect square, so a(4)=3.
CROSSREFS
KEYWORD
nonn
AUTHOR
Alex Ratushnyak, Oct 18 2013
EXTENSIONS
a(18)-a(21) from Jon E. Schoenfield, Oct 24 2013
a(22) from Jon E. Schoenfield, Oct 26 2013
a(23) from Jon E. Schoenfield, Oct 29 2013
More terms from Jon E. Schoenfield, Nov 26 2013
STATUS
approved