%I A144981
%S A144981 9,2,3,8,7,9,5,3,2,5,1,1,2,8,6,7,5,6,1,2,8,1,8,3,1,8,9,3,9,6,7,8,8,2,8,
%T A144981 6,8,2,2,4,1,6,6,2,5,8,6,3,6,4,2,4,8,6,1,1,5,0,9,7,7,3,1,2,8,0,5,3,5,0,
%U A144981 0,7,5,0,1,1,0,2,3,5,8,7,1,4,8,3,9,9,3,4,8,5,0,3,4,4,5,9,6,0,9,7,9,6,3
%N A144981 Decimal expansion of cos(Pi/8) = cos(22.5 degrees).
%C A144981 cos(Pi/5) is A019863. cos(Pi/6) is A010527. cos(Pi/7) is A073052. cos(Pi/
               9) is A019879.
%F A144981 (2+2^(1/2))^(1/2)/2 = sqrt(3.41421....)/2 = 1.8477759.../2 .
%F A144981 Equals 2F1(11/16,5/16;1/2;3/4) / 2. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), 
               Oct 27 2008]
%e A144981 Equals 0.923879532511286756128183189396788286822416625863642486115097...
%p A144981 evalf(sqrt(2+sqrt(2))/2) ;
%Y A144981 Sequence in context: A160108 A011344 A137197 this_sequence A133841 A099769 
               A020784
%Y A144981 Adjacent sequences: A144978 A144979 A144980 this_sequence A144982 A144983 
               A144984
%K A144981 cons,easy,nonn
%O A144981 0,1
%A A144981 R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 28 2008