OFFSET
1,4
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..500
EXAMPLE
a(4) = 2 since 4624 = 4^4 + 4^6 + 4^2 + 4^4 and 595968 = 4^5 + 4^9 + 4^5 + 4^9 + 4^6 + 4^8 and these are the only such numbers (see A139410).
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Chai Wah Wu, Dec 06 2017
STATUS
approved