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Triangle, A000012 * A131844 as infinite lower triangular matrices.
2

%I #8 Mar 04 2022 11:18:29

%S 1,5,4,12,5,7,22,6,8,10,35,7,9,11,13,51,8,10,12,14,16,70,9,11,13,15,

%T 17,19,92,10,12,14,16,18,20,22,117,11,13,15,17,19,21,23,25,145,12,14,

%U 16,18,20,22,24,26,28

%N Triangle, A000012 * A131844 as infinite lower triangular matrices.

%C Left column = pentagonal numbers, A000326: (1, 5, 12, 22, ...).

%C Row sums = A001106: (1, 9, 24, 46, 75, 111, ...).

%e First few rows of the triangle:

%e 1;

%e 5, 4;

%e 12, 5, 7;

%e 22, 6, 8, 10;

%e 35, 7, 9, 11, 13;

%e 51, 8, 10, 12, 14, 16;

%e 70, 9, 11, 13, 15, 17, 19;

%e 92, 10, 12, 14, 16, 18, 20, 22;

%e ...

%Y Cf. A131844, A001106, A000326.

%K nonn,tabl

%O 0,2

%A _Gary W. Adamson_, Jul 22 2007