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A027930
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T(n,2n-7), T given by A027926.
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0
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1, 3, 8, 21, 54, 133, 309, 674, 1383, 2683, 4950, 8735, 14820, 24285, 38587, 59652, 89981, 132771, 192052, 272841, 381314, 524997, 712977, 956134, 1267395, 1662011, 2157858, 2775763, 3539856, 4477949, 5621943, 7008264
(list; graph; refs; listen; history; internal format)
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OFFSET
| 4,2
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FORMULA
| a(n)=sum(binomial(n-k, 7-2k), k=0..3). - Len Smiley (smiley(AT)math.uaa.alaska.edu), Oct 20 2001
a(n)=C(n,n-1)+C(n+1,n-2)+C(n+2,n-3)+C(n+3,n-4), n>=1 . - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 29 2007
a(n)= 8*a(n-1) -28*a(n-2) +56*a(n-3) -70*a(n-4) +56*a(n-5) -28*a(n-6) +8*a(n-7) -a(n-8). G.f.: x^4*(x^2-x+1)*(x^4-4*x^3+7*x^2-4*x+1)/(x-1)^8. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 05 2009]
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MAPLE
| seq(binomial(n, n-1)+binomial(n+1, n-2)+binomial(n+2, n-3)+binomial(n+3, n-4), n=1..32); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 29 2007
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MATHEMATICA
| Table[Total[Binomial[First[#], Last[#]]&/@Table[{n+i, n-1-i}, {i, 0, 3}]], {n, 35}] (* or *) LinearRecurrence[{8, -28, 56, -70, 56, -28, 8, -1}, {1, 3, 8, 21, 54, 133, 309, 674}, 35] (* From Harvey P. Dale, June 23 2011 *)
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CROSSREFS
| Sequence in context: A039671 A166287 A186812 * A038200 A030015 A103446
Adjacent sequences: A027927 A027928 A027929 * A027931 A027932 A027933
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KEYWORD
| nonn
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AUTHOR
| Clark Kimberling (ck6(AT)evansville.edu)
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