login
A049354
Digitally balanced numbers in base 3: equal numbers of 0's, 1's, 2's.
14
11, 15, 19, 21, 260, 266, 268, 278, 290, 294, 302, 304, 308, 312, 316, 318, 332, 344, 348, 380, 384, 396, 410, 412, 416, 420, 424, 426, 434, 438, 450, 460, 462, 468, 500, 502, 508, 518, 520, 524, 528, 532, 534, 544, 550, 552, 572, 574, 578, 582, 586, 588, 596
OFFSET
1,1
LINKS
FORMULA
A062756(a(n)) = A077267(a(n)) and A081603(a(n)) = A077267(a(n)). - Reinhard Zumkeller, Aug 09 2014
MATHEMATICA
Select[Range[600], Length[Union[DigitCount[#, 3]]]== 1&]
FromDigits[#, 3]&/@DeleteCases[Flatten[Permutations/@Table[PadRight[{}, 3n, {1, 0, 2}], {n, 3}], 1], _?(#[[1]]==0&)]//Sort (* Harvey P. Dale, May 30 2016 *)
Select[Range@5000, Differences@DigitCount[#, 3]=={0, 0}&] (* Hans Rudolf Widmer, Dec 11 2021 *)
PROG
(Haskell)
a049354 n = a049354_list !! (n-1)
a049354_list = filter f [1..] where
f n = t0 == a062756 n && t0 == a081603 n where t0 = a077267 n
-- Reinhard Zumkeller, Aug 09 2014
(Python)
from sympy.ntheory import count_digits
def ok(n): c = count_digits(n, 3); return c[0] == c[1] == c[2]
print([k for k in range(600) if ok(k)]) # Michael S. Branicky, Nov 15 2021
CROSSREFS
KEYWORD
nonn,base
STATUS
approved