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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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified May 14 18:54 EDT 2021. Contains 343900 sequences. (Running on oeis4.)