OFFSET
1,2
REFERENCES
M. Lambrou, Solution to problem 2411, Crux Mathematicorum, Feb. 2000 26(1) 59-60 CMS.
PROG
(PARI) isok(n) = issquare(1 + (n-1)*n*(n+1)) \\ Michel Marcus, Jul 27 2013
CROSSREFS
KEYWORD
fini,nonn
AUTHOR
Lekraj Beedassy, Sep 02 2003
STATUS
approved