cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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.

Original entry on oeis.org

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

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Author

Alec Jones, Dec 24 2016

Keywords

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.
		

Crossrefs

Cf. A279968 for the similar array giving the number of prior elements of opposite parity.