A049354 Digitally balanced numbers in base 3: equal numbers of 0's, 1's, 2's.

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

Alois P. Heinz, Table of n, a(n) for n = 1..2000

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

Cf. A031443, A031944.

Cf. A049354-A049360. See also A061854, A037861.

Cf. A062756, A077267, A081603.

Sequence in context: A333488 A053675 A031944 * A343823 A105179 A120156

Adjacent sequences: A049351 A049352 A049353 * A049355 A049356 A049357

Keyword

nonn,base

Author

Harvey P. Dale

Status

approved