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A056158
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Equivalent of the Kurepa hypothesis for left factorial.
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1
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-4, -2, -4, 2, -20, 86, -532, 3706, -29668, 266990, -2669924, 29369138, -352429684, 4581585862, -64142202100, 962133031466, -15394128503492, 261700184559326, -4710603322067908, 89501463119290210, -1790029262385804244
(list; graph; refs; listen; history; internal format)
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OFFSET
| 3,1
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COMMENTS
| For a prime p>2 we have !p == -a(p) mod p, where the left factorial !n = sum_{k=0..n-1} k! (A003422).
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FORMULA
| a(3)=-4, a(n)=-(n-3)*a(n-1)-2*(n-1); or a(n)=2*(-1)^{n-1}*(n-3)!* Sum_{k=0}^{n-3} frac{(k+2)*(-1)^{k+1}}{k!}
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CROSSREFS
| Sequence in context: A010474 A064887 A114424 * A010316 A083954 A038702
Adjacent sequences: A056155 A056156 A056157 * A056159 A056160 A056161
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KEYWORD
| sign,easy
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AUTHOR
| Aleksandar Petojevic (apetoje(AT)ptt.yu), Jul 31 2000
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EXTENSIONS
| More terms from Larry Reeves (larryr(AT)acm.org), Oct 03 2000
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