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A012221 sech(arctan(arcsinh(x)))=1-1/2!*x^2+17/4!*x^4-769/6!*x^6+66401/8!*x^8... 0
1, -1, 17, -769, 66401, -9313281, 1927198833, -551835917697, 208856369686977, -100945109069282817, 60655475821737151953, -44346899335054478649345, 38762487400695339770533665 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
CROSSREFS
Sequence in context: A360647 A355495 A368492 * A012144 A265190 A308490
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved

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Last modified February 22 11:22 EST 2024. Contains 370254 sequences. (Running on oeis4.)