%I #9 Feb 08 2022 20:18:41
%S 1,3,2,5,6,3,7,8,9,4,9,10,11,12,5,11,12,13,14,15,6,13,14,15,16,17,18,
%T 7,15,16,17,18,19,20,21,8,17,18,19,20,21,22,23,24,9,19,20,21,22,23,24,
%U 25,26,27,10,21,22,23,24,25,26,27,28,29,30,11,23,24,25,26,27,28,29,30,31,32,33,12
%N Triangle read by rows, a(1) = 1, n-th row n terms of: (2n-1, 2n, 2n+1, ..., followed by n).
%C Row sums = A134238: (1, 5, 14, 28, 47, 71, 100, 134, ...).
%e First few rows of the triangle:
%e 1;
%e 3, 2;
%e 5, 6, 3;
%e 7, 8, 9, 4;
%e 9, 10, 11, 12, 5;
%e 11, 12, 13, 14, 15, 6;
%e 13, 14, 15, 16, 17, 18, 7;
%e ...
%o (PARI) T(n, k) = if (k < n, (2*n-1) + (k-1), n);
%o tabl(nn) = for (n=1, nn, for (k=1, n, print1(T(n, k), ", ")); print); \\ _Michel Marcus_, Jul 13 2017
%Y Cf. A134238.
%K nonn,tabl
%O 1,2
%A _Gary W. Adamson_, Oct 14 2007
%E Corrected and extended by _Michel Marcus_, Jul 13 2017
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