login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A359027
A line of empty cells is filled by successive terms t >= 1 with t+1 copies of t and gaps of t empty cells between them.
1
1, 2, 1, 3, 4, 2, 5, 6, 2, 3, 7, 8, 4, 3, 9, 10, 5, 3, 11, 4, 12, 6, 13, 14, 4, 5, 7, 15, 16, 4, 8, 6, 5, 17, 18, 9, 19, 7, 5, 20, 6, 10, 21, 22, 5, 8, 11, 23, 6, 7, 24, 12, 9, 25, 26, 6, 13, 8, 7, 27, 10, 28, 6, 14, 29, 30, 9, 7, 11, 8, 15, 31, 32, 16, 12, 7, 10
OFFSET
1,2
COMMENTS
We write 1 into the first cell, then by leaving a gap of one empty cell we write another 1 into the third cell.
Next, we write 2 into the first available empty cell, then write two more 2's by leaving gaps of two empty cells between them. And so on.
It appears that the absolute values of A166711 appear in order nicely embedded into this sequence. - Thomas Scheuerle, Dec 12 2022
EXAMPLE
Cell filling begins, starting from an empty line:
| | | | | | | | | | | | | | | | | | |
.
|1| |1| | | | | | | | | | | | | | | |
.
|1|2|1| | |2| | |2| | | | | | | | | |
.
|1|2|1|3| |2| | |2|3| | | |3| | | |3|
PROG
(MATLAB)
function a = A359027( max_n )
a = zeros(1, max_n);
f = 1:max_n; k = 1;
while ~isempty(f)
j = f(1:(k+1):end);
a(j(j(1:min(k+1, length(j))) <= max_n )) = k;
k = k+1;
f = find(a == 0);
end
end % Thomas Scheuerle, Dec 12 2022
CROSSREFS
Cf. A166711.
Cf. A028920 (with infinite copies).
Sequence in context: A117384 A358799 A125160 * A366691 A009947 A166711
KEYWORD
nonn,easy
AUTHOR
Tamas Sandor Nagy, Dec 12 2022
STATUS
approved