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A013195 E.g.f.: log(sec(x) + arcsin(x)). 1
0, 1, 0, 0, 4, -12, 72, -168, 544, 8144, -91520, 1384768, -11984128, 149032128, -1158162432, 16299168896, -125837340672, 2859883876608, -32260942757888, 1008997773326336, -15535095938220032, 466978134769624064 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

LINKS

Matthew House, Table of n, a(n) for n = 0..449

EXAMPLE

G.f. = x + 4*x^4 - 12*x^5 + 72*x^6 - 168*x^7 + 544*x^8 + 8144*x^9 - 91520*x^10 + ...

PROG

(PARI) {a(n) = my(A); if( n<0, 0, A = x * O(x^n); n! * polcoeff( log( 1 / cos(x + A) + asin(x + A) ), n))}; /* Michael Somos, Feb 17 2017 */

CROSSREFS

Sequence in context: A121771 A009621 A335907 * A323295 A166746 A052558

Adjacent sequences:  A013192 A013193 A013194 * A013196 A013197 A013198

KEYWORD

sign

AUTHOR

Patrick Demichel (patrick.demichel(AT)hp.com)

EXTENSIONS

a(0) corrected by Matthew House, Feb 16 2017

New name from Michael Somos, Feb 16 2017

STATUS

approved

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Last modified April 20 16:15 EDT 2021. Contains 343135 sequences. (Running on oeis4.)