%I A145502
%S A145502 2,6,46,2206,4870846,23725150497406,562882766124611619513723646,
%T A145502 316837008400094222150776738483768236006420971486980606
%N A145502 a(n+1)=a(n)^2+2*a(n)-2 and a(1)=2
%C A145502 General formula for a(n+1)=a(n)^2+2*a(n)-2 and a(1)=k+1 is a(n)=Floor[((k 
               + Sqrt[k^2 + 4])/2)^(2^((n+1) - 1))
%t A145502 aa = {}; k = 2; Do[AppendTo[aa, k]; k = k^2 + 2 k - 2, {n, 1, 10}]; aa
%t A145502 or
%t A145502 k = 1; Table[Floor[((k + Sqrt[k^2 + 4])/2)^(2^(n - 1))], {n, 2, 7}] (*Artur 
               Jasinski*)
%Y A145502 A145502-A145511
%Y A145502 Sequence in context: A078603 A001587 A078537 this_sequence A072444 A052596 
               A098710
%Y A145502 Adjacent sequences: A145499 A145500 A145501 this_sequence A145503 A145504 
               A145505
%K A145502 nonn
%O A145502 1,1
%A A145502 Artur Jasinski (grafix(AT)csl.pl), Oct 11 2008