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0, 12, 48, 108, 192, 300, 432, 588, 768, 972, 1200, 1452, 1728, 2028, 2352, 2700, 3072, 3468, 3888, 4332, 4800, 5292, 5808, 6348, 6912, 7500, 8112, 8748, 9408, 10092, 10800, 11532, 12288, 13068, 13872, 14700, 15552, 16428, 17328, 18252, 19200
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Areas of perfect 4:3 rectangles (for n>0).
Sequence found by reading the line from 0, in the direction 0, 12,..., in the square spiral whose vertices are the generalized octagonal numbers A001082. Semi-axis opposite to A069190 in the same spiral. - Omar E. Pol, Sep 16 2011
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FORMULA
| a(n) = A000290(n)*12 = A001105(n)*6 = A033428(n)*4 = A016742(n)*3 = A033581(n)*2. [From Omar E. Pol (info(AT)polprimos.com), Dec 13 2008]
a(n)=a(n-1)+24*n-12, n>0. [From Vincenzo Librandi, Nov 24 2010]
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EXAMPLE
| 192 is on the list since 16*12 is a 4:3 rectangle with integer sides and an area of 192
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MATHEMATICA
| Table[12*n^2, {n, 1, 60}] - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Dec 17 2007
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CROSSREFS
| Sequence in context: A044114 A044495 A009958 * A165280 A173548 A006564
Adjacent sequences: A135450 A135451 A135452 * A135454 A135455 A135456
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KEYWORD
| easy,nonn
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AUTHOR
| Ben Thurston (benthurston27(AT)yahoo.com), Dec 14 2007
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EXTENSIONS
| More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Dec 17 2007
Minor edits from Omar E. Pol (info(AT)polprimos.com), Dec 15 2008
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