cp's OEIS Frontend

A174658 Balanced ternary numbers with equal count of negative trits and positive trits.

%I A174658 #17 Apr 28 2021 10:10:53
%S A174658 0,2,6,8,16,18,20,24,26,32,46,48,52,54,56,60,62,70,72,74,78,80,86,96,
%T A174658 98,104,130,136,138,142,144,146,154,156,160,162,164,168,170,178,180,
%U A174658 182,186,188,194,208,210,214,216,218,222,224,232,234,236,240,242,248,258
%N A174658 Balanced ternary numbers with equal count of negative trits and positive trits.
%C A174658 Numbers for which the sum of trits is zero.
%H A174658 Daniel Forgues, <a href="/A174658/b174658.txt">Table of n, a(n) for n=1..14309</a>
%t A174658 (* First run the program for A065363 to define balTernDigits *) A174658 = Select[Range[0, 299], Plus@@balTernDigits[#] == 0 &] (* _Alonso del Arte_, Feb 24 2011 *)
%o A174658 (Python)
%o A174658 def a(n):
%o A174658     s=0
%o A174658     x=0
%o A174658     while n>0:
%o A174658         x=n%3
%o A174658         n //= 3
%o A174658         if x==2:
%o A174658             x=-1
%o A174658             n+=1
%o A174658         s+=x
%o A174658     return s
%o A174658 print([n for n in range(301) if a(n)==0]) # _Indranil Ghosh_, Jun 07 2017
%Y A174658 Cf. A174657, A174659, A065363, A140267, A257869.
%K A174658 base,nonn
%O A174658 1,2
%A A174658 _Daniel Forgues_, Mar 26 2010