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%I #9 Feb 17 2021 13:32:45
%S 0,1,2,1,3,2,1,4,5,2,1,5,3,7,2,1,6,7,8,9,2,1,7,4,3,5,11,2,1,8,9,10,11,
%T 12,13,2,1,9,5,11,3,13,7,15,2,1,10,11,4,13,14,5,16,17,2,1,11,6,13,7,3,
%U 8,17,9,19,2,1,12,13,14,15,16,17,18,19,20,21,2,1,13,7,5,4,17,3,19,5,7,11,23,2
%N Triangle read by rows: T(n,k) = (n+k)/gcd(n,k), n>=0, 0<=k<=n.
%C We define gcd(0,0) = 0.
%C This is half of the array A341314. See that entry for further information.
%e Triangle begins:
%e [0]
%e [1, 2]
%e [1, 3, 2]
%e [1, 4, 5, 2]
%e [1, 5, 3, 7, 2]
%e [1, 6, 7, 8, 9, 2]
%e [1, 7, 4, 3, 5, 11, 2]
%e [1, 8, 9, 10, 11, 12, 13, 2]
%e [1, 9, 5, 11, 3, 13, 7, 15, 2]
%e [1, 10, 11, 4, 13, 14, 5, 16, 17, 2]
%e [1, 11, 6, 13, 7, 3, 8, 17, 9, 19, 2]
%e [1, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 2]
%e ...
%Y Cf. A341314. A054531 is essentially the same triangle.
%Y See A341316 for the row sums.
%K nonn,tabl
%O 0,3
%A _N. J. A. Sloane_, Feb 17 2021
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