login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A073120 Areas of right triangles with integer sides. 5
6, 24, 30, 60, 84, 96, 120, 180, 210, 240, 330, 336, 384, 480, 486, 504, 546, 630, 720, 840, 924, 960, 990, 1224, 1320, 1344, 1386, 1536, 1560, 1710, 1716, 1920, 1944, 2016, 2184, 2310, 2340, 2430, 2520, 2574, 2730, 2880, 3036, 3360, 3570, 3696, 3750 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Areas of Pythagorean right triangles of the form (2mn, m^2-n^2, m^2+n^2), or equivalently integers of the form m*n*(m^2-n^2) where m,n are positive integers with m>n. - James Buddenhagen (jbuddenh(AT)gmail.com), Aug 10 2008

LINKS

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

Konstantine Hermes Zelator, A little noticed right triangle, arXiv: 0804.1340 [math.GM].

FORMULA

a(n) = A057102(n) / 4 [From Max Alekseyev (maxale(AT)gmail.com), Nov 14 2008]

EXAMPLE

6 = 3*4/2 is the area of the right triangle with sides 3 and 4.

84 = 7*24/2 is the area of the right triangle with sides 7 and 24.

MATHEMATICA

Union[Flatten[Table[m n (m^2-n^2), {m, 2, 50}, {n, 1, m-1}]]]

CROSSREFS

Cf. A002144, A003273, A046081, A057102, A024365.

Sequence in context: A057101 A057228 A132398 * A147778 A201596 A128459

Adjacent sequences:  A073117 A073118 A073119 * A073121 A073122 A073123

KEYWORD

easy,nonn

AUTHOR

Zak Seidov (zakseidov(AT)yahoo.com), Aug 25 2002

EXTENSIONS

Description corrected by James Buddenhagen (jbuddenh(AT)gmail.com), Aug 10 2008, and by Max Alekseyev (maxale(AT)gmail.com), Nov 12 2008

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 14 10:43 EST 2012. Contains 205614 sequences.