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A012851
sec(sec(x)*arctanh(x))=1+1/2!*x^2+25/4!*x^4+1225/6!*x^6+108113/8!*x^8...
0
1, 1, 25, 1225, 108113, 15283505, 3167087273, 904365439289, 340377095938337, 163284306442648801, 97251848546749385145, 70412470931263247515689, 60905917762268697815507057, 62032377805368358044198610705
OFFSET
0,3
CROSSREFS
Sequence in context: A120694 A012809 A014769 * A181719 A096330 A174751
KEYWORD
nonn
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved