%I #5 Feb 27 2023 07:05:07
%S 1,1,3,1,5,7,1,9,21,15,1,17,73,85,31,1,33,273,585,341,63,1,65,1057,
%T 4369,4681,1365,127,1,129,4161,33825,69905,37449,5461,255,1,257,16513,
%U 266305,1082401,1118481,299593,21845,511,1,513,65793,2113665,17043521,34636833,17895697,2396745,87381,1023
%N Array T(n,m) = (2^(n*m)-1)/(2^m-1) read by antidiagonals, n,m>=1.
%H Quynh Nguyen, Jean Pedersen, and Hien T. Vu, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL19/Pedersen/pedersen2.html">New Integer Sequences Arising From 3-Period Folding Numbers</a>, JIS vol 19 (2016) #16.3.1 table 1.
%F T(n,m) = (2^(n*m)-1)/(2^m-1) for n>1.
%e The array starts in rows n>=1 and columns m>=1 as
%e 1 1 1 1 1
%e 3 5 9 17 33
%e 7 21 73 273 1057
%e 15 85 585 4369 33825
%e 31 341 4681 69905 1082401
%Y Cf. A000225 (first col), A002450 (2nd col), A023001 (3rd col)
%K nonn,tabl,easy
%O 1,3
%A _R. J. Mathar_, Feb 27 2023