

A157933


Triangle T[i,j] such that sum_{j=0...i} T[i,j]*x[i,j]/2^i = sum_{k=0...i, j=0...k} x[k,j], if x[k1,j]=(x[k,j]+x[k,j+1])/2


0



1, 3, 3, 7, 10, 7, 15, 25, 25, 15, 31, 56, 66, 56, 31, 63, 119, 154, 154, 119, 63, 127, 246, 337, 372, 337, 246, 127, 255, 501, 711, 837, 837, 711, 501, 255, 511, 1012, 1468, 1804, 1930, 1804, 1468, 1012, 511
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OFFSET

0,2


COMMENTS

Rows and columns are numbered starting with 0. Consider a pyramid (triangle) where each element is the mean value of the two elements below. Then the sum of all elements is expressed as linear combination of the elements at the base. This sequence gives the coefficients times the necessary power of 2.


LINKS

Table of n, a(n) for n=0..44.


FORMULA

The first and last term in the (i+1)th row is T[i,0] = 2^(i+1)1.
The second and penultimate term is T[i,1] = T[i,0] + T[i1,1].


EXAMPLE

To get the 3rd row of the triangle, consider the pyramid
__f
_d e
a b c
where d=(a+b)/2, e=(b+c)/2, f=(d+e)/2. Then a+b+c+d+e+f=(7a+10b+7c)/2^2, which yields the row (7,10,7).


CROSSREFS

Sequence in context: A075149 A161618 A202873 * A013915 A136445 A052989
Adjacent sequences: A157930 A157931 A157932 * A157934 A157935 A157936


KEYWORD

nonn,tabl


AUTHOR

M. F. Hasler, Mar 16 2009


STATUS

approved



