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 A347499 Triangle read by rows: n-th row is the lexicographically earliest n-element subset of {1,2,3,...,A347498(n)} with the property that all products i * j are distinct for i <= j. 2

%I

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

%T 9,11,1,2,5,6,7,8,9,11,13,1,2,5,7,8,9,11,12,13,15,1,2,5,7,8,9,11,12,

%U 13,15,17,1,2,5,7,8,9,11,12,13,15,17,19

%N Triangle read by rows: n-th row is the lexicographically earliest n-element subset of {1,2,3,...,A347498(n)} with the property that all products i * j are distinct for i <= j.

%C Is the first column the all 1's sequence?

%e Triangle begins:

%e 1;

%e 1, 2;

%e 1, 2, 3;

%e 1, 2, 3, 5;

%e 1, 3, 4, 5, 6;

%e 1, 3, 4, 5, 6, 7;

%e 1, 2, 5, 6, 7, 8, 9;

%e 1, 2, 5, 6, 7, 8, 9, 11;

%e 1, 2, 5, 6, 7, 8, 9, 11, 13;

%e 1, 2, 5, 7, 8, 9, 11, 12, 13, 15;

%e 1, 2, 5, 7, 8, 9, 11, 12, 13, 15, 17;

%e 1, 2, 5, 7, 8, 9, 11, 12, 13, 15, 17, 19;

%e 1, 5, 6, 7, 9, 11, 13, 14, 15, 16, 17, 19, 20;

%e 1, 2, 5, 7, 11, 12, 13, 16, 17, 18, 19, 20, 21, 23;

%e ...

%Y A106683 is analogous for addition.

%Y Cf. A347498.

%K nonn,tabl

%O 1,3

%A _Peter Kagey_, Sep 03 2021

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Last modified January 28 17:08 EST 2023. Contains 359895 sequences. (Running on oeis4.)