login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A211676 Number of n-bit numbers in A077436. 1
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 (list; graph; refs; listen; history; text; internal format)
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 counts 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: A228669 A200444 A211697 * A076299 A136683 A200332

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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 4 09:05 EST 2016. Contains 278749 sequences.