cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A361618 Decimal expansion of the mean of the distribution of the least of the nine acute angles between pairs of edges of two randomly disoriented cubes (in radians).

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%I A361618 #12 Aug 09 2025 03:35:11
%S A361618 4,0,4,2,8,3,3,4,5,0,4,4,8,9,3,5,8,5
%N A361618 Decimal expansion of the mean of the distribution of the least of the nine acute angles between pairs of edges of two randomly disoriented cubes (in radians).
%C A361618 The angle in degrees is 23.1637293985...
%H A361618 Amiram Eldar, <a href="/A361618/a361618.txt">Mathematica code for A361618 and A361619</a>.
%H A361618 J. K. Mackenzie, <a href="http://www.jstor.org/stable/2333059">Second Paper on Statistics Associated with the Random Disorientation of Cubes</a>, Biometrika, Vol. 45, No. 1-2 (1958), pp. 229-240.
%H A361618 J. K. Mackenzie and M. J. Thomson, <a href="http://www.jstor.org/stable/2333253">Some Statistics Associated with the Random Disorientation of Cubes</a>, Biometrika, Vol. 44, No. 1-2 (1957), pp. 205-210.
%H A361618 Wikipedia, <a href="https://en.wikipedia.org/wiki/Misorientation">Misorientation</a>.
%F A361618 Equals Integral_{t=0..arccos(2/3)} t * P(t) dt, where P(t) = P1(t) if 0 <= t <= Pi/4, and P1(t) + P2(t) if Pi/4 < t <= arccos(2/3), and where
%F A361618 P1(t) = (288/Pi^2) * sin(t) * (Pi^2/32 - Integral_{x=0..Pi/4} arcsin(tan(t/2)*cos(x)) dx),
%F A361618 P2(t) = -(288/Pi^2) * sin(t) * (Pi*g(t)/4 - Integral_{x=Pi/4-g(t)..Pi/8+g(t)} arcsin(tan(t/2)*cos(x)) dx),
%F A361618 g(t) = arcsin(sqrt(((sqrt(2) + 1)^2 * tan(t/2)^2 - 1)/(4 * sqrt(2) * tan(t/2)^2))).
%e A361618 0.404283345044893585...
%t A361618 (* See the program in the links section. *)
%Y A361618 Cf. A228496, A361601, A361619, A361620, A361621.
%K A361618 nonn,cons,more
%O A361618 0,1
%A A361618 _Amiram Eldar_, Mar 18 2023