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A118247
a(0)=0. Concatenate onto the end of the sequence (from left to right) the integer m_n converted into binary (with the most significant digit on the left), where m_n is the smallest integer > A118248(n-1) and whose binary representation does not occur anywhere earlier in the sequence (when the concatenated sequence is read from left to right). A118248(n) then equals m_n when written in decimal.
9
0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0
OFFSET
0,1
COMMENTS
Sequence can be regarded as an irregular number triangle containing the binary digits of A118248(n) in row n. - Michael De Vlieger, Aug 19 2017
LINKS
Michael De Vlieger, Table of n, a(n) for n = 0..11419 (Concatenation of A118248(0) through A118248(1000) inclusive).
EXAMPLE
The sequence begins 0,1,1,0,1,0,0,1,1,1,1,0,0,0. Now A118248(5) = 8, which is represented by the 1,0,0,0 at the end of the sequence. The binary representation of 9 (1001 in binary) and (decimal) 10 (1010 in binary) both occur earlier in the sequence. But the binary representation of (decimal) 11 (1011 in binary) does not occur earlier in the sequence, so (1,0,1,1) is added to the end of the sequence. And A118248(6) becomes 11.
From Michael De Vlieger, Aug 19 2017: (Start)
n A118248(n) Binary digits appended to a(n)
0 0 0
1 1 1
2 2 10
3 4 100
4 7 111
5 8 1000
6 11 1011
7 16 10000
8 18 10010
9 21 10101
10 22 10110
11 25 11001
12 29 11101
(End)
MATHEMATICA
Block[{a = {{0}}, b = {0}, k, d}, Do[k = FromDigits[#, 2] &@ Last@ a + 1; While[SequenceCount[Flatten@ a, Set[d, IntegerDigits[k, 2]]] > 0, k++]; AppendTo[a, d]; AppendTo[b, k], {i, 22}]; Flatten@ a] (* Michael De Vlieger, Aug 19 2017 *)
CROSSREFS
KEYWORD
easy,nonn,base,tabf
AUTHOR
Leroy Quet, Apr 18 2006
EXTENSIONS
More terms from Joshua Zucker, Jul 27 2006
STATUS
approved