login
A039605
Numbers whose base-12 representation has the same nonzero number of 1's and 3's.
1
15, 37, 147, 171, 180, 182, 184, 185, 186, 187, 188, 189, 190, 191, 195, 207, 219, 231, 243, 255, 267, 279, 303, 325, 433, 444, 446, 448, 449, 450, 451, 452, 453, 454, 455, 457, 481, 493, 505, 517, 529, 541, 553, 565, 591, 613, 735, 757, 879, 901, 1023
OFFSET
1,1
LINKS
MAPLE
filter:= proc(n) local L, v;
L:= convert(n, base, 12);
v:= numboccur(1, L);
v > 0 and v = numboccur(3, L)
end proc:
select(filter, [$1..2000]); # Robert Israel, Dec 31 2019
MATHEMATICA
Select[Range[1100], DigitCount[#, 12, 1]==DigitCount[#, 12, 3]>0&] (* Harvey P. Dale, Apr 21 2011 *)
CROSSREFS
Sequence in context: A147221 A051461 A321383 * A032654 A320721 A086096
KEYWORD
nonn,base,easy
STATUS
approved