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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
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OFFSET
0,3
LINKS
Table of n, a(n) for n=0..12.
CROSSREFS
Sequence in context:
A360647
A355495
A368492
*
A012144
A265190
A308490
Adjacent sequences:
A012218
A012219
A012220
*
A012222
A012223
A012224
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved
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Last modified April 23 05:16 EDT 2024. Contains 371906 sequences. (Running on oeis4.)