

A143086


Symmetrical triangle sequence: t(n,m)=If[m < = ( less than or equal) Floor[n/2], 2^(m + 1)  1, 2^(n  m + 1)  1].


0



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, 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, 15, 7, 3, 1
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OFFSET

1,5


COMMENTS

Row sums are:A077866;
{1, 2, 5, 8, 15, 22, 37, 52, 83, 114, 177}.
The numbers are Mersenne like odd numbers.


LINKS

Table of n, a(n) for n=1..66.


FORMULA

t(n,m)=If[m < = ( less than or equal) Floor[n/2], 2^(m + 1)  1, 2^(n  m + 1)  1].


EXAMPLE

{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, 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, 15, 7, 3, 1}


MATHEMATICA

Table[Table[If[m < = Floor[n/2], 2^(m + 1)  1, 2^(n  m + 1)  1], {m, 0, n}], {n, 0, 10}]; Flatten'%]


CROSSREFS

Cf. A077866.
Sequence in context: A123191 A157454 A106255 * A327481 A152714 A174546
Adjacent sequences: A143083 A143084 A143085 * A143087 A143088 A143089


KEYWORD

nonn,uned


AUTHOR

Roger L. Bagula and Gary W. Adamson, Oct 16 2008


STATUS

approved



