OFFSET
0,3
COMMENTS
That is, the number of binary numbers b having n bits and B(b) = B(b^2), where the function B gives the number of ones in a binary number. For numbers written in base 10, the corresponding sequence is A147523.
MATHEMATICA
Join[{1}, Table[cnt = 0; Do[If[Total[IntegerDigits[i, 2]] == Total[IntegerDigits[i^2, 2]], cnt++], {i, 2^(n-1), 2^n-1}]; cnt, {n, 15}]]
CROSSREFS
KEYWORD
nonn,hard,base
AUTHOR
T. D. Noe, Apr 27 2012
EXTENSIONS
a(28)-a(38) from Donovan Johnson, Apr 29 2012
a(39)-a(40) from Donovan Johnson, Aug 25 2012
STATUS
approved