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A143074
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Numerator of Euler(n,2).
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6
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1, 3, 2, 9, 2, 3, 2, 33, 2, -27, 2, 699, 2, -5457, 2, 929601, 2, -3202287, 2, 221930589, 2, -4722116517, 2, 968383680843, 2, -14717667114147, 2, 2093660879252679, 2, -86125672563201177, 2, 129848163681107302017, 2, -868320396104950823607, 2, 209390615747646519456969
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OFFSET
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0,2
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LINKS
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FORMULA
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For even n, a(n) = 2 - delta(n,0), where delta is the Kronecker symbol;
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EXAMPLE
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By the formula, we have a(1) = 2*2 - 1 = 3, a(3) = 2*4 + 1 = 9, a(5) = 2*2 - 1 = 3, a(7) = 2*8 + 17 = 33, a(9) = 2*2 - 31 = -27, etc. - Vladimir Shevelev, Sep 04 2017
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MATHEMATICA
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CROSSREFS
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Cf. A002425, A157805, A157808, A157812, A157827, A157835, A157856, A157864, A157875, A157886, A157907.
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KEYWORD
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sign,frac
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AUTHOR
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STATUS
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approved
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