cp's OEIS Frontend

A131844 3*A131821 - 2.

%I A131844 #16 Apr 18 2024 15:32:34
%S A131844 1,4,4,7,1,7,10,1,1,10,13,1,1,1,13,16,1,1,1,1,16,19,1,1,1,1,1,19,22,1,
%T A131844 1,1,1,1,1,22,25,1,1,1,1,1,1,1,25,28,1,1,1,1,1,1,1,1,28,31,1,1,1,1,1,
%U A131844 1,1,1,1,31,34,1,1,1,1,1,1,1,1,1,1,34,37,1,1,1,1,1,1,1,1,1,1,1,37,40,1,1,1,1,1,1,1,1,1,1,1,1,40
%N A131844 3*A131821 - 2.
%C A131844 Row sums = A016993, (7n + 1): (1, 8, 15, 22, 29, ...).
%F A131844 3*A131821 - 2 as infinite lower triangular matrices.
%F A131844 Infinite lower triangular matrix, (3n + 1): (1, 4, 7, 10, ...) as right and left borders and the rest 1's.
%e A131844 First few rows of the triangle:
%e A131844    1;
%e A131844    4,  4;
%e A131844    7,  1,  7;
%e A131844   10,  1,  1, 10;
%e A131844   13,  1,  1,  1, 13;
%e A131844   16,  1,  1,  1,  1, 16;
%e A131844   ...
%Y A131844 Cf. A131821, A016993.
%K A131844 nonn,tabl
%O A131844 0,2
%A A131844 _Gary W. Adamson_, Jul 22 2007
%E A131844 More terms from _Russ Cox_, Apr 18 2024