A009675 - OEIS

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A009675

Tan(sin(x)^2) = 2/2!*x^2 - 8/4!*x^4 + 272/6!*x^6 - 13568/8!*x^8 + ...

0, 2, -8, 272, -13568, 1048832, -128073728, 21002749952, -4567924441088, 1269483920556032, -437557299535413248, 183472013004069404672, -91918408815486181572608, 54224850406884797340188672

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Robert Israel, Table of n, a(n) for n = 0..226

FORMULA

a(n) = 2 * A024264(n).

MAPLE

S:= series(tan(sin(x)^2), x, 101):

seq(coeff(S, x, j)*j!, j=0..100, 2); # Robert Israel, Apr 02 2017

MATHEMATICA

Tan[ Sin[ x ]^2 ] (* Even Part *)