A211676 Number of n-bit numbers in A077436.

1, 1, 2, 3, 4, 5, 6, 9, 14, 24, 37, 63, 93, 162, 233, 376, 582, 921, 1497, 2435, 4007, 6696, 10998, 18310, 30340, 50792, 84897, 143079, 239266, 401652, 673887, 1131226, 1900203, 3197114, 5373366, 9039360, 15208992, 25592325, 43064747, 72494816, 122025100

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.

Links

Table of n, a(n) for n=0..40.

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

Cf. A077436, A147523.

Sequence in context: A346074 A211697 A357570 * A076299 A341015 A136683

Adjacent sequences: A211673 A211674 A211675 * A211677 A211678 A211679

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