A131911 - OEIS

%I #6 Mar 05 2022 01:47:35

%S 1,4,3,5,2,5,8,1,2,7,9,2,1,2,9,12,1,2,1,2,11,13,2,1,2,1,2,13,16,1,2,1,

%T 2,1,2,15,17,2,1,2,1,2,1,2,17,20,1,2,1,2,1,2,1,2,19

%N 2*A131821 - A128174.

%C Left column, congruent to {0, 1} mod 4, A042948: (1, 4, 5, 8, 9, 12, 13, 16, ...).

%C Row sums = A131912: (1, 7, 12, 18, 23, 29, 34, ...).

%F 2*A131821 - A128174 as infinite lower triangular matrices.

%e First few rows of the triangle:

%e    1;

%e    4,  3;

%e    5,  2,  5;

%e    8,  1,  2,  7;

%e    9,  2,  1,  2,  9;

%e   12,  1,  2,  1,  2, 11;

%e   13,  2,  1,  2,  1,  2, 13;

%e   ...

%Y Cf. A131821, A128174, A042948, A131912.

%K nonn,tabl

%O 1,2

%A _Gary W. Adamson_, Jul 27 2007