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A119782
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Numerator of Sum[ i^3/(n-i+1)^2, {i,1,n}].
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0
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1, 33, 262, 10325, 7227, 923027, 4588732, 49631229, 29087285, 1618749187, 152762993, 69307256941, 191848206263, 702044812445, 9181629908344, 2873944084323677, 1547933530301469, 1198197057199579439
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OFFSET
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1,2
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COMMENTS
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Prime p divides a(2p-1). Prime p divides a(3p-1), p>2. Prime p divides a(p-1), p>2. p^2 divides a(p^2-1) for prime p>2. p^3 divides a(p^3-1) for prime p>2. p^4 divides a(p^4-1) for prime p>2. p^5 divides a(p^5-1) for prime p>2.
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LINKS
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Table of n, a(n) for n=1..18.
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FORMULA
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a(n) = numerator[ Sum[i^3/(n-i+1)^2, {i,1,n}]].
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MATHEMATICA
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Numerator[Table[Sum[i^3/(n-i+1)^2, {i, 1, n}], {n, 1, 50}]]
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CROSSREFS
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Cf. A007406, A001008, A027612.
Sequence in context: A197347 A197398 A061223 * A008515 A179995 A000539
Adjacent sequences: A119779 A119780 A119781 * A119783 A119784 A119785
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KEYWORD
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frac,nonn
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AUTHOR
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Alexander Adamchuk, Jun 25 2006
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STATUS
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approved
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