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A100259
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Coefficient of x^2 in 2n-th normalized Legendre polynomial.
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1
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3, -30, 105, -1260, 3465, -18018, 45045, -875160, 2078505, -9699690, 22309287, -202811700, 456326325, -2035917450, 4508102925, -158685222960, 347123925225, -1511010027450, 3273855059475, -28258538408100
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OFFSET
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1,1
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LINKS
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EXAMPLE
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Example: Legendre(12) = (676039x^12 - 1939938x^10 + 2078505x^8 - 1021020x^6 + 225225x^4 - 18018x^2 + 231)/1024, hence a(6) = -18018. - Neven Juric
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PROG
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(PARI) a(n) = polcoeff(pollegendre(2*n, x), 2)*2^valuation((2*n)!, 2) \\ Michel Marcus, May 29 2013
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CROSSREFS
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3rd column (without zeros) of triangle A100258.
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KEYWORD
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sign
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AUTHOR
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EXTENSIONS
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Definition corrected by Neven Juric, Jan 10 2009
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STATUS
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approved
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