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COMMENTS
| Same as Pisot sequences E(2,8), L(2,8), P(2,8), T(2,8). See A008776 for definitions of Pisot sequences.
In the Chebyshev polynomial of degree 2n, a(n) is the coefficient of x^2n. - Benoit Cloitre (benoit7848c(AT)orange.fr), Mar 13 2002
1/2 - 1/8 + 1/32 - 1/128 + ... = 2/5 [From Gary W. Adamson (qntmpkt(AT)yahoo.com), Mar 03 2009]
Numbers n such that n^3+(n/2)^3=9*n^3/8 is a square. [From Vincenzo Librandi, Nov 18 2010]
From Adi Dani, May 15 2011: (Start)
Number of ways of placing an even number of undistinguishable objects in n+1 distinguishable boxes with at most 3 objects in box.
Number of compositions of even natural numbers into n+1 parts <=3 (0 is counted as part). (End)
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EXAMPLE
| From Adi Dani, May 15 2011: (Start)
a(1)=8 because all compositions of even natural numbers into 2 parts <=3 are
for 0: (0,0)
for 2: (0,2),(2,0),(1,1)
for 4: (1,3),(3,1),(2,2)
for 6: (3,3).
a(2)=32 because all compositions of even natural numbers into 3 parts <=3 are
for 0: (0,0,0)
for 2: (0,0,2), (0,2,0), (2,0,0), (0,1,1), (1,0,1) , (1,1,0)
for 4: (0,1,3), (0,3,1), (1,0,3), (1,3,0), (3,0,1), (3,1,0), (0,2,2), (2,0,2), (2,2,0), (1,1,2), (1,2,1), (2,1,1)
for 6: (0,3,3), (3,0,3), (3,3,0), (1,2,3), (1,3,2), (2,1,3), (2,3,1), (3,1,2), (3,2,1), (2,2,2)
for 8: (2,3,3), (3,2,3), (3,3,2).
(End)
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