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A112094
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Denominator of 3*Sum_{i=1..n} 1/(i^2*C(2*i,i)).
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1
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1, 2, 8, 120, 672, 5600, 79200, 50450400, 201801600, 10291881600, 17776886400, 2151003254400, 3805621142400, 643149973065600, 643149973065600, 31085582031504000, 226741892465088000, 65528406922410432000, 31039771700089152000, 414598230598090803264000, 16583929223923632130560
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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REFERENCES
| C. Elsner, On recurrence formulae for sums involving binomial coefficients, Fib. Q., 43 (No. 1, 2005), 31-45.
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FORMULA
| 3*Sum_{i=1..infinity} 1/(i^2*C(2*i, i)) = zeta(2) = Pi^2/6.
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MAPLE
| 0, 3/2, 13/8, 197/120, 1105/672, 9211/5600, 130277/79200, 82987349/50450400, ... -> Pi^2/6.
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CROSSREFS
| Cf. A112093.
Sequence in context: A012347 A099292 A064111 * A009658 A147794 A027530
Adjacent sequences: A112091 A112092 A112093 * A112095 A112096 A112097
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KEYWORD
| nonn,frac
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Nov 30 2005
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