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”).

A343934
Irregular triangle read by rows: row n gives the sequence of iterations of k - A006519(k), starting with k=n, until 0 is reached.
1
1, 2, 3, 2, 4, 5, 4, 6, 4, 7, 6, 4, 8, 9, 8, 10, 8, 11, 10, 8, 12, 8, 13, 12, 8, 14, 12, 8, 15, 14, 12, 8, 16, 17, 16, 18, 16, 19, 18, 16, 20, 16, 21, 20, 16, 22, 20, 16, 23, 22, 20, 16, 24, 16, 25, 24, 16, 26, 24, 16, 27, 26, 24, 16, 28, 24, 16
OFFSET
1,2
COMMENTS
Row n starts with n, then the highest power of 2 dividing n is subtracted to produce the next entry in the row.
n first appears at position A000788(n)+1.
LINKS
EXAMPLE
The triangle begins
1
2
3 2
4
5 4
6 4
7 6 4
MATHEMATICA
Table[Most @ NestWhileList[# - 2^IntegerExponent[#, 2] &, n, # > 0 &], {n, 1, 30}] // Flatten (* Amiram Eldar, May 05 2021 *)
PROG
(Python)
def gen_a():
for n in range(1, 100):
k = n
while k>0:
yield k
k = k & (k-1)
a = gen_a()
CROSSREFS
Cf. A000120 (row widths), A000788, A006519, A129760, A298011 (row sums).
Sequence in context: A304098 A239690 A208460 * A119465 A359369 A090321
KEYWORD
nonn,easy,tabf
AUTHOR
Christian Perfect, May 04 2021
STATUS
approved