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A104583 Triangle read by rows: T(i,j) is the (i,j)-entry (1<=j<=i) of the product A*B of the matrices A = [1; 3,1; 5,3,1; 7,5,3,1;...]; B = [1; 1,2; 1,2,1; 1,2,1,2; ...] (both infinite lower triangular matrices). +0
1
1, 4, 2, 9, 8, 1, 16, 18, 4, 2, 25, 32, 9, 8, 1, 36, 50, 16, 18, 4, 2, 49, 72, 25, 32, 9, 8, 1, 64, 98, 36, 50, 16, 18, 4, 2, 81, 128, 49, 72, 25, 32, 9, 8, 1, 100, 162, 64, 98, 36, 50, 16, 18, 4, 2, 121, 200, 81, 128, 49, 72, 25, 32, 9, 8, 1, 144, 242, 100, 162, 64, 98, 36, 50, 16, 18 (list; table; graph; listen)
OFFSET

0,2

FORMULA

T(i, j)=(i-j+1)^2 if j<=i and j is odd; 2(i-j+1)^2 if j<=i and j is even; 0 if j>i. - Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 23 2005

EXAMPLE

The first few rows are:

1;

4, 2;

9, 8, 1;

16, 18, 4, 2;

25, 32, 9, 8, 1;

36, 50, 16, 18, 4, 2;

49, 72, 25, 32, 9, 8, 1;

...

MAPLE

T:=proc(i, j) if j<=i and j mod 2=1 then (i-j+1)^2 elif j<=i and j mod 2 =0 then 2*(i-j+1)^2 else 0 fi end: for i from 1 to 13 do seq(T(i, j), j=1..i) od; # yields sequence in triangular form (Deutsch)

CROSSREFS

Cf. A002411.

Row sums yield the pentagonal pyramidal numbers (A002411).

Sequence in context: A082156 A114577 A101690 this_sequence A097664 A052915 A130273

Adjacent sequences: A104580 A104581 A104582 this_sequence A104584 A104585 A104586

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson (qntmpkt(AT)yahoo.com), Mar 16 2005

EXTENSIONS

More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 23 2005

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Last modified August 19 23:53 EDT 2008. Contains 142930 sequences.


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