|
|
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
|
if n::even then 4*procname(n/2-1)+3
else 4*procname((n-1)/2)+2
fi
end proc;
|
|
MATHEMATICA
|
Select[Range[1000], Min[IntegerDigits[#, 4]]>1&] (* Harvey P. Dale, Dec 23 2013 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|