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A141666 A symmetrical triangle of coefficients based on A004018 (or number of ways of writing n as a sum of 2 squares): t(n,m)=r2(n-m+1)*r2(m+1). +0
1
1, 4, 4, 4, 16, 4, 0, 16, 16, 0, 4, 0, 16, 0, 4, 8, 16, 0, 0, 16, 8, 0, 32, 16, 0, 16, 32, 0, 0, 0, 32, 0, 0, 32, 0, 0, 4, 0, 0, 0, 16, 0, 0, 0, 4, 4, 16, 0, 0, 32, 32, 0, 0, 16, 4, 8, 16, 16, 0, 0, 64, 0, 0, 16, 16, 8 (list; graph; listen)
OFFSET

1,2

COMMENT

Row sums are:

{1, 8, 24, 32, 24, 48, 96, 64, 24, 104, 144}.

REFERENCES

http : // mathworld.wolfram.com/SumofSquaresFunction.html

G. E. Andrews, Number Theory, 1971, Dover Publications New York, p 44,p 201-207.

FORMULA

t(n,m)=r2(n-m+1)*r2(m+1).

EXAMPLE

{1},

{4, 4},

{4, 16, 4},

{0, 16, 16, 0},

{4, 0, 16, 0, 4},

{8, 16, 0, 0, 16, 8},

{0, 32, 16, 0, 16, 32, 0},

{0, 0, 32, 0, 0, 32, 0, 0},

{4, 0, 0, 0, 16, 0, 0, 0, 4},

{4, 16, 0, 0, 32, 32, 0, 0, 16, 4},

{8, 16, 16, 0, 0, 64, 0, 0, 16, 16, 8}

MATHEMATICA

Clear[a] a = Table[SeriesCoefficient[Series[1 + 4Sum[(-1)^(1 + n)/(-1 + x^(1 - 2*n)), {n, 100}], {x, 0, 100}], n], {n, 0, 100}]; Table[Table[a[[n - m + 1]]*a[[m + 1]], {m, 0, n}], {n, 0, 10}]; Flatten[%]

CROSSREFS

Cf. A004018.

Sequence in context: A151906 A151896 A098525 this_sequence A102127 A131946 A034896

Adjacent sequences: A141663 A141664 A141665 this_sequence A141667 A141668 A141669

KEYWORD

nonn,uned

AUTHOR

Roger L. Bagula and Gary W. Adamson (rlbagulatftn(AT)yahoo.com), Sep 05 2008

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Last modified November 27 22:38 EST 2009. Contains 167602 sequences.


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