cp's OEIS Frontend

A350776 Nonnegative integers whose balanced ternary expansion has no two consecutive nonzero digits.

%I A350776 #5 Jan 24 2022 16:13:30
%S A350776 0,1,3,8,9,10,24,26,27,28,30,71,72,73,78,80,81,82,84,89,90,91,213,215,
%T A350776 216,217,219,233,234,235,240,242,243,244,246,251,252,253,267,269,270,
%U A350776 271,273,638,639,640,645,647,648,649,651,656,657,658,699,701,702
%N A350776 Nonnegative integers whose balanced ternary expansion has no two consecutive nonzero digits.
%C A350776 This sequence is to balanced ternary what A328727 is to ternary.
%F A350776 A350775(n) = 0 iff n belongs to the present sequence.
%e A350776 The first terms, in decimal and in balanced ternary, are:
%e A350776   n   a(n)  bter(n)
%e A350776   --  ----  -------
%e A350776    1     0        0
%e A350776    2     1        1
%e A350776    3     3       10
%e A350776    4     8      10T
%e A350776    5     9      100
%e A350776    6    10      101
%e A350776    7    24     10T0
%e A350776    8    26     100T
%e A350776    9    27     1000
%e A350776   10    28     1001
%e A350776   11    30     1010
%e A350776   12    71    10T0T
%o A350776 (PARI) is(n) = { my (p=0, d); while (n, d=[0, 1, -1][1+n%3]; if (p && d, return (0), n=(n-d)/3; p=d)); 1 }
%Y A350776 Cf. A059095, A328727, A350775.
%K A350776 nonn,base
%O A350776 1,3
%A A350776 _Rémy Sigrist_, Jan 15 2022