OFFSET
1,3
COMMENTS
If a number k is of the form 2^(2*r), r >= 0, then k is included in this sequence.
EXAMPLE
225 is in the sequence because it is a square and the number of 1's in the binary expansion of 225 is 4 which is a square.
MAPLE
q:= n-> issqr(add(i, i=Bits[Split](n))):
select(q, [i^2$i=0..250])[]; # Alois P. Heinz, Nov 03 2021
MATHEMATICA
Select[Range[0, 300]^2, IntegerQ @ Sqrt[DigitCount[#, 2, 1]] &] (* Amiram Eldar, Nov 03 2021 *)
PROG
(PARI) isok(k) = issquare(k) && issquare(hammingweight(k)); \\ Michel Marcus, Nov 03 2021
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Ctibor O. Zizka, Nov 03 2021
STATUS
approved