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A347317
An alternative version of the inventory sequence A342585: now a row only ends when a 0 is reached that would not be followed by any further terms.
9
0, 1, 1, 0, 2, 2, 2, 0, 3, 2, 4, 1, 1, 0, 4, 4, 4, 1, 4, 0, 5, 5, 4, 1, 6, 2, 1, 0, 6, 7, 5, 1, 6, 3, 3, 1, 0, 7, 9, 5, 3, 6, 4, 4, 2, 0, 1, 0, 9, 10, 6, 4, 9, 4, 5, 2, 0, 3, 1, 0, 11, 11, 7, 5, 10, 6, 6, 3, 0, 3, 2, 2, 0
OFFSET
0,5
COMMENTS
This sequence has offset 0, which seems more appropriate than the offset 1 that A342585 has.
In both A342585 and the present sequence, a row records the numbers of 0's, 1's, 2's, etc., in the sequence so far.
The difference is that in A342585 a row ends when the first 0 is reached. The row beginning 7, for example, is 7, 9, 5, 3, 6, 4, 4, 2, 0, and ends, because there is no 8 in the sequence up to this point. However, there is a 9, so we can say that the row ended prematurely.
In the present sequence we continue the row until we reach a 0 which is 1 more than the highest term in the sequence up to that point, and then the row ends.
So the row beginning 7 is now 7, 9, 5, 3, 6, 4, 4, 2, 0, 1, 0.
From this point on the two sequences differ.
Unfortunately, this version has the drawback that most of the entries are zero!
LINKS
EXAMPLE
The triangle begins:
0;
1, 1, 0;
2, 2, 2, 0;
3, 2, 4, 1, 1, 0;
4, 4, 4, 1, 4, 0;
5, 5, 4, 1, 6, 2, 1, 0;
6, 7, 5, 1, 6, 3, 3, 1, 0;
7, 9, 5, 3, 6, 4, 4, 2, 0, 1, 0;
9, 10, 6, 4, 9, 4, 5, 2, 0, 3, 1, 0;
11, 11, 7, 5, 10, 6, 6, 3, 0, 3, 2, 2, 0;
...
MATHEMATICA
Block[{c, k, m, r = 0}, c[0] = 1; {0}~Join~Reap[Do[k = 0; While[k <= r, If[IntegerQ@ c[k], Set[m, c[k]], Set[c[k], 0]; Set[m, 0]]; If[m > r, r = m]; Sow[m]; If[IntegerQ@ c[m], c[m]++, c[m] = 1]; k++]; Sow[0]; c[0]++, 9]][[-1, -1]]] (* Michael De Vlieger, Oct 12 2021 *)
PROG
(Python)
from collections import Counter
def aupton(terms):
num, alst, inventory = 0, [0], Counter([0])
for n in range(2, terms+1):
c = inventory[num]
if c == 0 and num > max(inventory):
num = 0
else:
num += 1
alst.append(c); inventory.update([c])
return alst
print(aupton(73)) # Michael S. Branicky, Sep 09 2021
CROSSREFS
Cf. A342585. See A347318 for row lengths.
Sequence in context: A197727 A176884 A308361 * A342585 A348288 A345730
KEYWORD
nonn,tabf
AUTHOR
N. J. A. Sloane, Sep 09 2021
STATUS
approved