%I #8 Jun 07 2023 06:21:50
%S 1,4,3,7,6,5,10,9,8,7,13,12,11,10,9,16,15,14,13,12,11,19,18,17,16,15,
%T 14,13,22,21,20,19,18,17,16,15,25,24,23,22,21,20,19,18,17,28,27,26,25,
%U 24,23,22,21,20,19,31,30,29,28,27,26,25,24,23,22,21,34,33,32,31,30,29,28,27,26,25,24,23
%N Triangle read by rows: A002024 + A128076 - A000012 as infinite lower triangular matrices.
%C Row sums = A000566, the heptagonal numbers: (1, 7, 18, 34, 55, ...).
%F By rows, (n+1) terms of 3n+1, 3n, 3n-1, ...
%e First few rows of the triangle:
%e 1;
%e 4, 3;
%e 7, 6, 5;
%e 10, 9, 8, 7;
%e 13, 12, 11, 10, 9;
%e 16, 15, 14, 13, 12, 11;
%e 19, 18, 17, 16, 15, 14, 13;
%e ...
%Y Cf. A000566, A002024, A128076.
%K nonn,tabl
%O 0,2
%A _Gary W. Adamson_, Jul 08 2007
%E a(5) = 5, a(30) = 20 corrected and more terms from _Georg Fischer_, Jun 07 2023