%I A011922
%S A011922 1,3,33,451,6273,87363,1216801,16947843,236052993,3287794051,
%T A011922 45793063713,637815097923,8883618307201,123732841202883,
%U A011922 1723376158533153,24003533378261251,334326091137124353
%N A011922 (2+sqrt(1+((((2+sqrt(3))^(2*n)-(2-sqrt(3))^(2*n))^2)/4)))/3.
%D A011922 Mario Velucchi, Seeing couples, in Recreational and Educational Computing, 
               to appear 1997.
%F A011922 sqrt 3 = 1 + Sum(1 through infinity) 2/a(n) = 2/2 + 2/3 + 2/33 + 2/451 
               + 2/6273 + 2/87363 + 2/1216801... - Gary W. Adamson (qntmpkt(AT)yahoo.com), 
               Jun 12 2003
%F A011922 a(n)^2 = A103974(n+1)^2 - (4*A007655(n+1))^2. - Paul D. Hanna (pauldhanna(AT)juno.com), 
               Mar 06 2005
%Y A011922 Cf. A011916, A011918, A011920.
%Y A011922 Cf. A103974, A007655.
%Y A011922 Sequence in context: A163476 A155660 A009502 this_sequence A071405 A092170 
               A083080
%Y A011922 Adjacent sequences: A011919 A011920 A011921 this_sequence A011923 A011924 
               A011925
%K A011922 nonn,easy
%O A011922 0,2
%A A011922 Mario Velucchi (mathchess(AT)velucchi.it)
%E A011922 Formula corrected by Francisco Salinas (franciscodesalinas(AT)hotmail.com), 
               Dec 30 2001