The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A032804 Numbers whose set of base-4 digits is {2,3}. 4
2, 3, 10, 11, 14, 15, 42, 43, 46, 47, 58, 59, 62, 63, 170, 171, 174, 175, 186, 187, 190, 191, 234, 235, 238, 239, 250, 251, 254, 255, 682, 683, 686, 687, 698, 699, 702, 703, 746, 747, 750, 751, 762, 763, 766, 767, 938, 939, 942 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Or, no base-2 digit of a(n) is a base-4 digit of a(n).
LINKS
FORMULA
a(0) = 0, a(2*n) = 4*a(n-1) + 3, a(2*n+1) = 4*a(n)+2. - Robert Israel, May 05 2014
MAPLE
A032804:= proc(n) option remember;
if n::even then 4*procname(n/2-1)+3
else 4*procname((n-1)/2)+2
fi
end proc;
A032804(0):=0; # Robert Israel, May 05 2014
MATHEMATICA
Select[Range[1000], Min[IntegerDigits[#, 4]]>1&] (* Harvey P. Dale, Dec 23 2013 *)
CROSSREFS
Cf. A007090.
Sequence in context: A285622 A081706 A359251 * A248407 A047473 A270474
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 22 20:45 EDT 2024. Contains 372758 sequences. (Running on oeis4.)