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A374362 a(n) is the least term t of A005836 such that n - t also belongs to A005836.

%I A374362 #13 Jul 10 2024 02:59:10
%S A374362 0,0,1,0,0,1,3,3,4,0,0,1,0,0,1,3,3,4,9,9,10,9,9,10,12,12,13,0,0,1,0,0,
%T A374362 1,3,3,4,0,0,1,0,0,1,3,3,4,9,9,10,9,9,10,12,12,13,27,27,28,27,27,28,
%U A374362 30,30,31,27,27,28,27,27,28,30,30,31,36,36,37,36
%N A374362 a(n) is the least term t of A005836 such that n - t also belongs to A005836.
%C A374362 To compute a(n): in the ternary expansion of n, replace 1's by 0's and 2's by 1's.
%H A374362 Rémy Sigrist, <a href="/A374362/b374362.txt">Table of n, a(n) for n = 0..6561</a>
%F A374362 a(n) = A374361(n, 0).
%F A374362 a(n) = n - A374363(n).
%F A374362 a(n) >= 0 with equality iff n belongs to A374361.
%F A374362 a(n) = A005836(1 + A289814(n)).
%e A374362 The first terms, in decimal and in ternary, are:
%e A374362   n   a(n)  ter(n)  ter(a(n))
%e A374362   --  ----  ------  ---------
%e A374362    0     0       0          0
%e A374362    1     0       1          0
%e A374362    2     1       2          1
%e A374362    3     0      10          0
%e A374362    4     0      11          0
%e A374362    5     1      12          1
%e A374362    6     3      20         10
%e A374362    7     3      21         10
%e A374362    8     4      22         11
%e A374362    9     0     100          0
%e A374362   10     0     101          0
%e A374362   11     1     102          1
%e A374362   12     0     110          0
%e A374362   13     0     111          0
%e A374362   14     1     112          1
%e A374362   15     3     120         10
%o A374362 (PARI) a(n) = fromdigits(apply(d -> [0, 0, 1][1+d], digits(n, 3)), 3)
%o A374362 (Python)
%o A374362 from gmpy2 import digits
%o A374362 def A374362(n): return int(digits(n,3).replace('1','0').replace('2','1'),3) # _Chai Wah Wu_, Jul 09 2024
%Y A374362 Cf. A005836, A289814, A374361.
%K A374362 nonn,base
%O A374362 0,7
%A A374362 _Rémy Sigrist_, Jul 06 2024