A249865 Characteristic array for odd divisors of n, n >= 1 (with rows ending in a 1).

1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1

Offset

1

Comments

The row length sequence is A003602(n).

The row sums are A001227(n).

This entry is motivated by A237048.

For all divisors see the triangle A051731.

Links

Table of n, a(n) for n=1..78.

Formula

For n>=1 and k = 1, 2, ..., A003602(n): T(n, k) = 1 if 2*k-1 divides n else 0.

Example

The irregular triangle T(n, k) begins (m = 2*k-1):
n\k 1  2  3  4  5  6  7  8  9 10 ...
  m 1  3  5  7  9 11 13 15 17 19 ...
1:  1
2:  1
3:  1  1
4:  1
5:  1  0  1
6:  1  1
7:  1  0  0  1
8:  1
9:  1  1  0  0  1
10: 1  0  1
11: 1  0  0  0  0  1
12: 1  1
13: 1  0  0  0  0  0  1
14: 1  0  0  1
15: 1  1  1  0  0  0  0  1
16: 1
17: 1  0  0  0  0  0  0  0  1
18: 1  1  0  0  1
19: 1  0  0  0  0  0  0  0  0  1
20: 1  0  1
...

Crossrefs

Cf. A003602, A001227, A051731, A237048.

Sequence in context: A141679 A276254 A303300 * A152904 A249133 A118102

Adjacent sequences: A249862 A249863 A249864 * A249866 A249867 A249868

Keyword

nonn,easy,tabf

Author

Wolfdieter Lang, Nov 12 2014

Status

approved