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 A243280 Expansion of log'(1/2-sqrt((5*x+2*sqrt(1-4*x)-2)/x)/2). 0
 1, 3, 13, 63, 325, 1748, 9685, 54841, 315605, 1838610, 10811788, 64041706, 381525253, 2283436938, 13718099275, 82672421423, 499546587317, 3025336228390, 18357852413062, 111587292429820, 679306584310220 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS FORMULA a(n) = sum(k=0..n, binomial(2*k-1,k)*binomial(2*n,n-k)). a(n) ~ 5^(2*n+1/2) / (sqrt(3*Pi*n) * 2^(2*n+1)). - Vaclav Kotesovec, Jun 06 2014 MATHEMATICA Table[Sum[Binomial[2 i - 1, i] Binomial[2 n, n - i], {i, 0, n}], {n, 0, 20}] (* Wesley Ivan Hurt, Jun 06 2014 *) PROG (Maxima) a(n):=sum(binomial(2*k-1, k)*binomial(2*n, n-k), k, 0, n); CROSSREFS Sequence in context: A026715 A001850 A130525 * A000259 A007855 A193112 Adjacent sequences:  A243277 A243278 A243279 * A243281 A243282 A243283 KEYWORD nonn AUTHOR Vladimir Kruchinin, Jun 02 2014 STATUS approved

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Last modified April 18 08:37 EDT 2019. Contains 322209 sequences. (Running on oeis4.)