A135151 - OEIS

%I #6 Mar 27 2022 18:27:33

%S 1,1,2,2,2,3,1,3,3,4,2,2,4,4,5,1,3,3,5,5,6,2,2,4,4,6,6,7,1,3,3,5,5,7,

%T 7,8,2,2,4,4,6,6,8,8,9,1,3,3,5,5,7,7,9,9,10

%N A002260 + A128174 - I, I = Identity matrix.

%C A135152 is a companion triangle, both having row sums = A047838: (1, 3, 7, 11, 17, 23, 31, 39, ...).

%F A002260 + A128174 - I, where I = Identity matrix, A002260 = (1; 1,2; 1,2,3; ...) and A128174 = (1; 0,1; 1,0,1; 0,1,0,1; ...).

%e First few rows of the triangle:

%e   1;

%e   1, 2;

%e   2, 2, 3;

%e   1, 3, 3, 4;

%e   2, 2, 4, 4, 5;

%e   1, 3, 3, 5, 5, 6;

%e   2, 2, 4, 4, 6, 6, 7;

%e   ...

%Y Cf. A002260, A047838, A135152.

%K nonn,tabl

%O 1,3

%A _Gary W. Adamson_, Nov 21 2007