cp's OEIS Frontend

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.

%I A279965 #20 Jun 03 2018 02:03:58
%S A279965 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,
%T A279965 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,
%U A279965 6,5,10,9,6,12,8,13,11,8,12,14
%N 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.
%H A279965 Peter Kagey, <a href="/A279965/b279965.txt">Table of n, a(n) for n = 1..5000</a>
%e A279965 The array is constructed along its antidiagonals, in the following way:
%e A279965 .
%e A279965 a(1)  a(3)  a(6)  a(10)
%e A279965 a(2)  a(5)  a(9)
%e A279965 a(4)  a(8)
%e A279965 a(7)
%e A279965 .
%e A279965 ----------------------------------------------------------
%e A279965 n       a(n)       array
%e A279965 ----------------------------------------------------------
%e A279965 1       0          0
%e A279965 .
%e A279965 2       1          0
%e A279965                    1
%e A279965 .
%e A279965 3       1          0 1
%e A279965                    1
%e A279965 .
%e A279965 4       1          0 1
%e A279965                    1
%e A279965                    1
%e A279965 .
%e A279965 5       3          0 1
%e A279965                    1 3
%e A279965                    1
%e A279965 .
%e A279965 6       1          0 1 1
%e A279965                    1 3
%e A279965                    1
%e A279965 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.
%Y A279965 Cf. A279968 for the similar array giving the number of prior elements of opposite parity.
%K A279965 nonn,tabl
%O A279965 1,5
%A A279965 _Alec Jones_, Dec 24 2016