A133981 - OEIS

%I #9 Jun 07 2023 04:40:46

%S 1,4,3,5,6,5,6,7,8,7,7,8,9,10,9,8,9,10,11,12,11,9,10,11,12,13,14,13,

%T 10,11,12,13,14,15,16,15,11,12,13,14,15,16,17,18,17,12,13,14,15,16,17,

%U 18,19,20,19,13,14,15,16,17,18,19,20,21,22,21,14,15,16,17,18,19,20,21,22,23,24,23

%N Triangle read by rows: A000012 * A127701 + A127701 * A000012 - A000012 as infinite lower triangular matrices.

%C Row sums = A133694: (1, 7, 16, 28, 43, 61, ...).

%e First few rows of the triangle:

%e    1;

%e    4,  3;

%e    5,  6,  5;

%e    6,  7,  8,  7;

%e    7,  8,  9, 10,  9;

%e    8,  9, 10, 11, 12, 11;

%e    9, 10, 11, 12, 13, 14, 13;

%e   10, 11, 12, 13, 14, 15, 16, 15;

%e   11, 12, 13, 14, 15, 16, 17, 18, 17;

%e   ...

%Y Cf. A127701, A133694.

%K nonn,tabl

%O 1,2

%A _Gary W. Adamson_, Sep 30 2007

%E a(26) = 13 corrected and more terms from _Georg Fischer_, Jun 07 2023