|
|
A033048
|
|
Sums of distinct powers of 12.
|
|
7
|
|
|
0, 1, 12, 13, 144, 145, 156, 157, 1728, 1729, 1740, 1741, 1872, 1873, 1884, 1885, 20736, 20737, 20748, 20749, 20880, 20881, 20892, 20893, 22464, 22465, 22476, 22477, 22608, 22609, 22620, 22621, 248832, 248833, 248844, 248845, 248976
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
COMMENTS
|
Numbers without any base-12 digits greater than 1.
|
|
LINKS
|
|
|
FORMULA
|
a(n) = Sum_{i=0..m} d(i)*12^i, where Sum_{i=0..m} d(i)*2^i is the base-2 representation of n.
a(2n) = 12*a(n), a(2n+1) = a(2n)+1.
G.f.: (1/(1 - x))*Sum_{k>=0} 12^k*x^(2^k)/(1 + x^(2^k)). - Ilya Gutkovskiy, Jun 04 2017
|
|
MATHEMATICA
|
With[{k = 12}, Map[FromDigits[#, k] &, Tuples[{0, 1}, 6]]] (* Michael De Vlieger, Oct 28 2022 *)
|
|
PROG
|
(PARI) {maxn=37;
for(vv=0, maxn,
bvv=binary(vv);
ll=length(bvv); texp=0; btod=0;
forstep(i=ll, 1, -1, btod=btod+bvv[i]*12^texp; texp++);
print1(btod, ", "))}
(Haskell)
import Data.List (unfoldr)
a033048 n = a033048_list !! (n-1)
a033048_list = filter (all (< 2) . unfoldr (\x ->
if x == 0 then Nothing else Just $ swap $ divMod x 12)) [1..]
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base,easy
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|