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Revision History for A012378

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Showing entries 1-10 | older changes
A012378 tan(tan(x)*arcsin(x))=2/2!*x^2+12/4!*x^4+430/6!*x^6+26040/8!*x^8...
(history; published version)
#12 by Vaclav Kotesovec at Fri Feb 06 09:32:25 EST 2015
STATUS

editing

approved

#11 by Vaclav Kotesovec at Fri Feb 06 09:32:13 EST 2015
FORMULA

a(n) ~ 2*cos(r) * ( * (2*n)! / ((arcsin(r)/cosPi/sin(2*r) + sintan(r)/sqrt(1-r^2)) * r^(2*n+1)), where r = 0.925530521691094119047741289850... is the root of the equation tan(r)*arcsin(r) = Pi/2. - Vaclav Kotesovec, Feb 06 2015

Discussion
Fri Feb 06 09:32
Vaclav Kotesovec: Simplified.
#10 by Vaclav Kotesovec at Fri Feb 06 09:07:51 EST 2015
FORMULA

a(n) ~ 2*cos(r) * (sin(arcsin(r)*tan(r)))^2 * (2*n)! / ((arcsin(r)/cos(r) + sin(r)/sqrt(1-r^2)) * r^(2*n+1)), where r = 0.925530521691094119047741289850... is the root of the equation tan(r)*arcsin(r) = Pi/2. - Vaclav Kotesovec, Feb 06 2015

STATUS

approved

editing

#9 by Vaclav Kotesovec at Fri Feb 06 08:45:47 EST 2015
STATUS

editing

approved

#8 by Vaclav Kotesovec at Fri Feb 06 08:44:45 EST 2015
FORMULA

a(n) ~ 2*cos(r) * (sin(arcsin(r)*tan(r)))^2 * (2*n)! / ((arcsin(r)/cos(r) + sin(r)/sqrt(1-r^2)) * r^(2*n+1)), where r = 0.925530521691094119047741289850... is the root of the equation tan(r)*arcsin(r) = Pi/2. - Vaclav Kotesovec, Feb 06 2015

#7 by Vaclav Kotesovec at Fri Feb 06 08:30:40 EST 2015
LINKS

Vaclav Kotesovec, <a href="/A012378/b012378.txt">Table of n, a(n) for n = 0..220</a>

#6 by Vaclav Kotesovec at Fri Feb 06 08:05:08 EST 2015
MATHEMATICA

nn = 20; Table[(CoefficientList[Series[Tan[ArcSin[x]*Tan[x]], {x, 0, 2*nn}], x] * Range[0, 2*nn]!)[[n]], {n, 1, 2*nn+1, 2}] (* Vaclav Kotesovec, Feb 06 2015 *)

#5 by Vaclav Kotesovec at Fri Feb 06 03:30:01 EST 2015
DATA

0, 2, 12, 430, 26040, 2661178, 402231940, 84456360742, 23476965450736, 8341678414816242, 3686586514781799292, 1982979948714026781726, 1275341677617693817452200, 966341800352400737116306986

OFFSET

0,12

EXTENSIONS

a(0)=0 prepended by Vaclav Kotesovec, Feb 06 2015

STATUS

approved

editing

#4 by Charles R Greathouse IV at Fri Feb 24 12:50:48 EST 2012
AUTHOR

Patrick Demichel (dmlpatrick.demichel(AT)hpfrcu03.france.hp.com)

Discussion
Fri Feb 24 12:50
OEIS Server: https://oeis.org/edit/global/108
#3 by N. J. A. Sloane at Fri May 16 03:00:00 EDT 2003
KEYWORD

nonn,new

nonn

AUTHOR

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

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Last modified September 11 13:11 EDT 2024. Contains 375829 sequences. (Running on oeis4.)