OFFSET
0,4
LINKS
EXAMPLE
For n = 5:
- the binary representation of 5 is "101",
- the possible values for (x, y), restricted to x >= y without loss of generality, are:
bin(5) x y x^2+y^2
------- - - -------
"101" 5 0 25
"1/01" 1 1 2
"10/1" 2 1 5
"1/0/1" 3 0 9
- hence a(5) = 2.
PROG
(C) See Links section.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Jan 04 2020
STATUS
approved