OFFSET
1,1
COMMENTS
Luca and Togbe showed that there are no other terms.
LINKS
F. Luca and A. Togbe, On the Diophantine Equation x^2 + 2^a 5^b y^n, Int. J. Number Theory 4 (2008), 973-979.
EXAMPLE
a(2) = 729 = 23^2 + 2^3 * 5^2 = 3^6 = 9^3, a(8) = 315821241 = 17771^2 + 2^9 * 5^2 = 681^3.
CROSSREFS
KEYWORD
nonn,fini,full
AUTHOR
Tomohiro Yamada, Nov 18 2017
STATUS
approved