OFFSET
0,3
COMMENTS
Indexing starts from zero as a(0) = 0 is a special case in this sequence.
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..9616
EXAMPLE
1 can be represented as 1*1 (1 being "1" also in base-2 system), thus it is included.
4 can be represented as 2*2, and like any square, is included.
6 can be represented as 2*3, and both "10" and "11" require two bits in binary system, thus 6 is included.
MATHEMATICA
{0}~Join~Flatten[Position[#, k_ /; k > 0] &@ Table[Length@ DeleteCases[Flatten@ Map[Differences@ IntegerLength[#, 2] &, Transpose@ {#, n/#}] &@ TakeWhile[Divisors@ n, # <= Sqrt@ n &], k_ /; k > 0], {n, 400}]] (* Michael De Vlieger, Dec 30 2015 *)
CROSSREFS
KEYWORD
AUTHOR
Antti Karttunen, Dec 28 2015
STATUS
approved