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A073746
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Decimal expansion of sech(1).
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8
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6, 4, 8, 0, 5, 4, 2, 7, 3, 6, 6, 3, 8, 8, 5, 3, 9, 9, 5, 7, 4, 9, 7, 7, 3, 5, 3, 2, 2, 6, 1, 5, 0, 3, 2, 3, 1, 0, 8, 4, 8, 9, 3, 1, 2, 0, 7, 1, 9, 4, 2, 0, 2, 3, 0, 3, 7, 8, 6, 5, 3, 3, 7, 3, 1, 8, 7, 1, 7, 5, 9, 5, 6, 4, 6, 7, 1, 2, 8, 3, 0, 2, 8, 0, 8, 5, 4, 7, 8, 5, 3, 0, 7, 8, 9, 2, 8, 9, 2, 3, 8, 4, 8, 4
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OFFSET
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0,1
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COMMENTS
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sech(x) = 2/(e^x + e^(-x)).
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REFERENCES
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Samuel M. Selby (ed.), CRC Basic Mathematical Tables, CRC Press, 1970, p. 218.
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LINKS
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FORMULA
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Equals Sum_{k>=0} E(2*k) / (2*k)!, where E(k) is the k-th Euler number (A122045). - Amiram Eldar, May 15 2021
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EXAMPLE
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0.64805427366388539957497735322...
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MATHEMATICA
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RealDigits[Sech[1], 10, 100][[1]] (* Amiram Eldar, May 15 2021 *)
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PROG
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(PARI) 1/cosh(1)
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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