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Irregular triangle read by rows: successive rows have lengths 1,3,5,7,..., and are filled in across rows with the smallest nonnegative number such that there is no repeat in any row, column, or diagonal of slope +-1.
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%I #14 Jun 01 2017 09:09:25

%S 0,1,2,3,2,0,4,1,5,3,1,5,6,0,4,2,4,5,0,2,1,7,3,6,8,5,3,1,4,6,8,9,2,7,

%T 0,10,6,4,2,0,3,9,5,10,11,1,12,7,13,7,8,9,5,4,6,10,3,2,12,0,11,14,15,

%U 1,8,6,10,3,7,2,11,4,9,13,1,5,15,12,16,14,17

%N Irregular triangle read by rows: successive rows have lengths 1,3,5,7,..., and are filled in across rows with the smallest nonnegative number such that there is no repeat in any row, column, or diagonal of slope +-1.

%C Conjecture: every column or diagonal of slope +-1 is a permutation of the nonnegative numbers.

%H Alois P. Heinz, <a href="/A286297/b286297.txt">Rows n = 0..200, flattened</a>

%e Triangle begins:

%e ..........0,

%e ........1,2,3,

%e ......2,0,4,1,5,

%e ....3,1,5,6,0,4,2,

%e ..4,5,0,2,1,7,3,6,8,

%e 5,3,1,4,6,8,9,2,7,0,10,

%e ...

%Y Inspired by A274528, A274641, A274650.

%K nonn,tabf

%O 0,3

%A _N. J. A. Sloane_, Jun 01 2017

%E More terms from _Alois P. Heinz_, Jun 01 2017