Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #18 Feb 08 2022 22:08:24
%S 1,2,1,3,1,3,4,1,3,7,5,1,3,7,15,6,1,3,7,15,31,7,1,3,7,15,31,63,8,1,3,
%T 7,15,31,63,127,9,1,3,7,15,31,63,127,255,10,1,3,7,15,31,63,127,255,511
%N Triangle read by rows, "n" followed by (n-1) terms of (1, 3, 7, 15, ...).
%C Sum of terms in n-th row = rightmost term in next row.
%e First few rows of the triangle:
%e 1;
%e 2, 1;
%e 3, 1, 3;
%e 4, 1, 3, 7;
%e 5, 1, 3, 7, 15;
%e 6, 1, 3, 7, 15, 31;
%e 7, 1, 3, 7, 15, 31, 63;
%e ...
%Y Cf. A000225 (row sums).
%K nonn,tabl,easy
%O 1,2
%A _Gary W. Adamson_, Sep 01 2008