OFFSET
1,2
COMMENTS
Conjectured to be a permutation of the natural numbers.
The central polygonal numbers can be constructed by starting with the natural numbers, setting A000124(0)=1 and obtaining A000124(n+1) by reversing the order of the next A000124(n) numbers after A000124(n). This procedure doesn't produce a permutation of the natural numbers for A000124 because the sequence is strictly increasing. The present sequence is constructed by the same procedure, except that a(n+1) is obtained by reversing the next a(A004738(n)) numbers.
LINKS
Max Barrentine, Table of n, a(n) for n = 1..1124
EXAMPLE
Start with the natural numbers:
1, 2, 3, 4, 5, 6, 7, 8, 9...
a(A004738(1))=1, so reverse the order of the next term, leaving the sequence unchanged:
(1)
1, (2), 3, 4, 5, 6, 7, 8, 9...
a(A004738(2))=2, so reverse the order of the next 2 terms:
(2)
1, 2, (4, 3), 5, 6, 7, 8, 9...
a(A004738(3))=1, so reverse the order of the next term, leaving the sequence unchanged:
(1)
1, 2, 4, (3), 5, 6, 7, 8, 9...
a(A004738(4))=2, so reverse the order of the next 2 terms:
(2)
1, 2, 4, 3, (6, 5), 7, 8, 9...
a(A004738(5))=4, so reverse the order of the next 4 terms:
(4)
1, 2, 4, 3, 6, (9, 8, 7, 5)...
a(A004738(6))=2, so reverse the order of the next 2 terms:
(2)
1, 2, 4, 3, 6, 9, (7, 8), 5...
a(A004738(7))=1, so reverse the order of the next term, leaving the sequence unchanged:
(1)
1, 2, 4, 3, 6, 9, 7, (8), 5...
CROSSREFS
KEYWORD
nonn
AUTHOR
Max Barrentine, Apr 16 2016
STATUS
approved