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%I #13 Jun 22 2020 07:00:44
%S 0,1,2,2,3,4,4,5,6,6,7,8,8,9,10,10,11,11,12,13,13,14,15,15,16,17,17,
%T 18,18,19,20,20,21,22,22,23,24,24,25,25,26,27,27,28,29,29,30,31,31,32,
%U 32,33,34,34,35,36,36,37,38,38,39,39,40,41,41,42,43,43,44
%N a(n) = round(tan(Pi*(1-1/n)/2)).
%p f := n->round(evalf(tan((1-1/n)*Pi/2)));
%o (PARI) a(n) = round(tan(Pi*(1-1/n)/2)); \\ _Michel Marcus_, Jun 22 2020
%Y Cf. A024811 (with floor).
%K nonn
%O 1,3
%A _N. J. A. Sloane_.
%E Offset corrected and more terms from _Sean A. Irvine_, Jun 22 2020