%I #16 Jul 28 2016 09:13:23
%S 5,21,88,369,1547,6486,27193,114009,477993,2004029,8402073,35226452,
%T 147690090,619204077,2596069167,10884255079,45633225081,191321428631,
%U 802132415328,3363012791217,14099735676764,59114418676555,247842553617931,1039102350307282
%N Pisot sequence E(5,21), a(n) = floor( a(n-1)^2/a(n-2) + 1/2 ).
%H Colin Barker, <a href="/A010917/b010917.txt">Table of n, a(n) for n = 0..1000</a>
%H D. W. Boyd, <a href="http://matwbn.icm.edu.pl/ksiazki/aa/aa34/aa3444.pdf">Some integer sequences related to the Pisot sequences</a>, Acta Arithmetica, 34 (1979), 295-305.
%H D. W. Boyd, <a href="https://www.researchgate.net/profile/David_Boyd7/publication/262181133_Linear_recurrence_relations_for_some_generalized_Pisot_sequences_-_annotated_with_corrections_and_additions/links/00b7d536d49781037f000000.pdf">Linear recurrence relations for some generalized Pisot sequences</a>, Advances in Number Theory ( Kingston ON, 1991) 333-340, Oxford Sci. Publ., Oxford Univ. Press, New York, 1993.
%t RecurrenceTable[{a[0]==5,a[1]==21,a[n]==Floor[a[n-1]^2/a[n-2]+1/2]}, a[n],{n,30}] (* _Harvey P. Dale_, Sep 24 2011 *)
%o (PARI) pisotE(nmax, a1, a2) = {
%o a=vector(nmax); a[1]=a1; a[2]=a2;
%o for(n=3, nmax, a[n] = floor(a[n-1]^2/a[n-2]+1/2));
%o a
%o }
%o pisotE(50, 5, 21) \\ _Colin Barker_, Jul 28 2016
%K nonn
%O 0,1
%A _Simon Plouffe_