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A012121
sec(arcsin(arcsinh(x)))=1+1/2!*x^2+5/4!*x^4+109/6!*x^6+3177/8!*x^8...
0
1, 1, 5, 109, 3177, 227961, 15773229, 2521786149, 294715261521, 91106569198449, 14283819393505749, 8353531761471301725, 1366332291998753348025, 1671117489759750577634025, 171277162439935833445571325, 660477991317304143815464418325
OFFSET
0,3
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Sec[ArcSin[ArcSinh[x]]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Oct 09 2017 *)
CROSSREFS
Sequence in context: A195552 A318292 A012239 * A371882 A376462 A014180
KEYWORD
nonn
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
More terms from Harvey P. Dale, Oct 09 2017
STATUS
approved