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A012831 cosh(sec(x)*arcsinh(x))=1+1/2!*x^2+9/4!*x^4+225/6!*x^6+6993/8!*x^8... 0
1, 1, 9, 225, 6993, 467745, 29529753, 4297350785, 378759492257, 122599030798017, 8002975063348265, 9354851201922233249, -686072407102337430543, 1787263355638656126843105 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

CROSSREFS

Sequence in context: A067405 A063386 A063392 * A012749 A188662 A079727

Adjacent sequences:  A012828 A012829 A012830 * A012832 A012833 A012834

KEYWORD

sign

AUTHOR

Patrick Demichel (dml(AT)hpfrcu03.france.hp.com)

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Last modified February 15 23:53 EST 2012. Contains 205860 sequences.