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A215990
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Numerator of sum( k!/2^k, k=1..n ).
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2
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0, 1, 1, 7, 13, 7, 73, 461, 1721, 7391, 35741, 95833, 140902, 7208291, 6221977, 738064507, 5846167507, 49265043007, 440034922507, 4152348777757, 41275487330257, 431068442131507, 4718790944945257, 27013799863651691, 322866652557800441, 502628413904332477
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OFFSET
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0,4
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COMMENTS
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If a(n) is even, then A215976(n)=0 (and n is listed in A215974); the converse is not necessarily true.
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LINKS
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MATHEMATICA
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Table[Numerator[Sum[k!/2^k, {k, n}]], {n, 0, 30}] (* Harvey P. Dale, Jul 02 2017 *)
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PROG
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(PARI) a(n)=numerator(sum(k=1, n, k!/2^k))
(PARI) s=0; for(k=1, 29, print1(numerator(s+=k!/2^k), ", "))
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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