A143086 - OEIS

%I #19 Jun 08 2023 09:37:44

%S 1,1,1,1,3,1,1,3,3,1,1,3,7,3,1,1,3,7,7,3,1,1,3,7,15,7,3,1,1,3,7,15,15,

%T 7,3,1,1,3,7,15,31,15,7,3,1,1,3,7,15,31,31,15,7,3,1,1,3,7,15,31,63,31,

%U 15,7,3,1,1,3,7,15,31,63,63,31,15,7,3,1,1,3,7,15,31,63,127,63,31,15,7,3,1

%N Triangle read by rows: T(n,k) = 2^(k + 1) - 1 if k < = floor(n/2), otherwise 2^(n - k + 1) - 1, for 0 <= k <= n.

%e {1},

%e {1,  1},

%e {1,  3,  1},

%e {1,  3,  3,  1},

%e {1,  3,  7,  3,  1},

%e {1,  3,  7,  7,  3,  1},

%e {1,  3,  7, 15,  7,  3,  1},

%e {1,  3,  7, 15, 15,  7,  3,  1},

%e {1,  3,  7, 15, 31, 15,  7,  3,  1},

%e {1,  3,  7, 15, 31, 31, 15,  7,  3,  1},

%e {1,  3,  7, 15, 31, 63, 31, 15,  7,  3,  1}

%t Table[Table[If[m < = Floor[n/2], 2^(m + 1) - 1, 2^(n - m + 1) - 1], {m, 0, n}], {n, 0, 10}]; Flatten'%]

%Y Cf. A077866 (row sums).

%K nonn,tabl,easy,less

%O 0,5

%A _Roger L. Bagula_ and _Gary W. Adamson_, Oct 16 2008

%E Offset changed to 0 by _Georg Fischer_, Jun 08 2023