A279965 Square array read by antidiagonals upwards in which each term is the number of prior elements in the same row, column, diagonal, or antidiagonal whose parity is the same as the parity of n.
0, 1, 1, 1, 3, 1, 2, 1, 5, 2, 2, 2, 5, 3, 4, 3, 4, 3, 8, 4, 4, 3, 5, 3, 7, 3, 9, 4, 4, 3, 8, 6, 6, 8, 6, 11, 4, 4, 8, 8, 5, 9, 7, 7, 7, 5, 6, 5, 6, 8, 8, 12, 9, 7, 8, 5, 7, 5, 7, 8, 12, 9, 13, 5, 15, 8, 6, 5, 10, 9, 6, 12, 8, 13, 11, 8, 12, 14
Offset: 1
Examples
The array is constructed along its antidiagonals, in the following way:
.
a(1) a(3) a(6) a(10)
a(2) a(5) a(9)
a(4) a(8)
a(7)
.
----------------------------------------------------------
n a(n) array
----------------------------------------------------------
1 0 0
.
2 1 0
1
.
3 1 0 1
1
.
4 1 0 1
1
1
.
5 3 0 1
1 3
1
.
6 1 0 1 1
1 3
1
For example, a(5) = 3 because 5 has the same parity as a(2), a(3), and a(4), which are in the same row, column, and antidiagonal, respectively.
Links
- Peter Kagey, Table of n, a(n) for n = 1..5000
Crossrefs
Cf. A279968 for the similar array giving the number of prior elements of opposite parity.