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A257869
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Nonnegative integers with an equal number of occurrences of all trits in balanced ternary representation.
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5
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6, 8, 136, 138, 144, 154, 156, 160, 164, 168, 170, 180, 186, 188, 208, 210, 214, 218, 222, 224, 232, 236, 248, 258, 260, 266, 288, 294, 296, 312, 314, 320, 3406, 3412, 3414, 3430, 3432, 3438, 3484, 3486, 3492, 3510, 3568, 3574, 3576, 3592, 3594, 3600, 3622
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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LINKS
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Alois P. Heinz, Table of n, a(n) for n = 1..10000
Wikipedia, Balanced ternary
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EXAMPLE
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6 = 1L0_bal3, 8 = 10L_bal3, 136 = 1LL001_bal3, 138 = 1LL010_bal3, 144 = 1LL100_bal3, where L represents (-1).
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MAPLE
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p:= proc(n) local d, m, r; m:=n; r:=0;
while m>0 do
d:= irem(m, 3, 'm');
if d=2 then m:=m+1 fi;
r:= r+x^d
od;
simplify(r/(1+x+x^2))::integer
end:
a:= proc(n) option remember; local k;
for k from 1+`if`(n=1, 0, a(n-1)) by 1
while not p(k) do od; k
end:
seq(a(n), n=1..70);
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PROG
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(Python)
def a(n):
s=[]
x=0
while n>0:
x=n%3
n//=3
if x==2:
x=-1
n+=1
s.append(x)
return s
print([n for n in range(1, 5001) if a(n).count(1)==a(n).count(-1) and a(n).count(-1)==a(n).count(0)]) # Indranil Ghosh, Jun 07 2017
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CROSSREFS
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Cf. A117967, A140267, A257867, A257868, A258410.
Subsequence of A174658.
Sequence in context: A324987 A013239 A013235 * A201387 A013236 A013242
Adjacent sequences: A257866 A257867 A257868 * A257870 A257871 A257872
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KEYWORD
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nonn,base
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AUTHOR
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Alois P. Heinz, May 11 2015
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STATUS
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approved
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