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A109222
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Row sums of a triangle related to the Fibonacci polynomials.
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4
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1, 2, 3, 6, 11, 21, 40, 76, 145, 276, 526, 1002, 1909, 3637, 6929, 13201, 25150, 47915, 91286, 173915, 331337, 631252, 1202640, 2291229, 4365172, 8316378, 15844082, 30185609, 57508601, 109563441, 208736561, 397677834, 757642355, 1443434582
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Row sums of A109221.
The Kn4 sums, see A180662, of triangle A065941 equal the terms of this sequence a(n) while the Kn4 sums of triangle A194005 equal a(n+1)-1. [Johannes W. Meijer, Aug 14 2011]
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FORMULA
| G.f.: (1+x-x^2-x^3)/(1-x-2x^2+x^4); a(n)=a(n-1)+2a(n-2)-a(n-4); a(n)=sum{k=0..n, binomial(floor((2n-k)/2)+n-k, 2n-2k)}.
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MAPLE
| A109222 := proc(n): add(binomial(floor((2*n-k)/2)+n-k, 2*n-2*k), k=0..n) end: seq(A109222(n), n=0..33); # [Johannes W. Meijer, Aug 14 2011]
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CROSSREFS
| Sequence in context: A123915 A132832 A079116 * A191789 A006861 A052956
Adjacent sequences: A109219 A109220 A109221 * A109223 A109224 A109225
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KEYWORD
| easy,nonn
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Jun 22 2005
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