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A120644 Area common to integer-sided isosceles triangles (x,x,y) and (x,x,z=y+2d), sorted on x>z/2, d being positive. 1
12, 60, 120, 168, 420, 420, 360, 1260, 660, 1848, 1008, 2640, 2772, 1092, 3120, 4680, 1980, 5460, 1680, 5148, 9240, 3432, 2448, 7140, 11220, 14280, 8580, 3420, 15912, 10032, 15960, 5460, 20748, 15708, 23940, 4620, 13260, 21840, 25080, 8160, 23712 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

x=A020882(n) ; y=2*A046086(n) ; z=2*A046087(n) ; d=A120682(n). y is twice the height of the other triangle with z as base and conversely.

FORMULA

a(n) = y*z/4 = A046086(n)*A046087(n) = 2*A120734(n).

EXAMPLE

168 in the sequence refers to the area common to both triangle (25,25,14) and triangle (25,25,48).

CROSSREFS

Sequence in context: A012406 A097191 A094807 * A099829 A099830 A158443

Adjacent sequences:  A120641 A120642 A120643 * A120645 A120646 A120647

KEYWORD

easy,nonn

AUTHOR

Lekraj Beedassy (blekraj(AT)yahoo.com), Aug 17 2006, Aug 20 2006

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Last modified February 18 00:14 EST 2012. Contains 206085 sequences.