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Triangle read by rows in which the n-th row contains n numbers not occurring earlier such that every entry is coprime to all the members of the row and column it belongs.
3

%I #6 Dec 05 2013 19:56:03

%S 1,2,3,5,4,7,9,11,8,13,17,19,15,14,23,29,25,31,27,16,37,41,43,47,53,

%T 21,10,59,49,61,67,55,71,39,32,73,79,83,89,97,65,77,51,38,101,103,91,

%U 107,109,113,127,95,33,34,131,121,137,139,149,151,157,161,85,57,26,163,167

%N Triangle read by rows in which the n-th row contains n numbers not occurring earlier such that every entry is coprime to all the members of the row and column it belongs.

%C Observation: The second leading diagonal contains even numbers and all other diagonals mandatorily contain odd numbers. (Proof?)

%e Triangle begins:

%e 1

%e 2 3

%e 5 4 7

%e 9 11 8 13

%e 17 19 15 14 23

%e ...

%Y Cf. A081995, A081996, A081997.

%K tabl,nonn

%O 1,2

%A _Amarnath Murthy_, Apr 05 2003

%E Corrected and extended by Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 29 2003