A071383

[cloitre]

Numseq fans :

A071383 says :

        
1,5,25,65,325,1105,4225,5525,27625,71825,138125,160225,801125,2082925,
4005625,5928325,29461625,77068225,148208125,243061325

%N A071383 Squared radius of first circle around (0,0) with more points of
the square lattice on its circumference than on any smaller circle around
(0,0).
%C A071383 The number of lattice points (i,j) on the circle with
i^2+j^2=a(n) is given by A071385(n)
%Y A071383 Cf. A071384, A071385.
%K A071383 more,nonn,new
%O A071383 1,2
%A A071383 Hugo Pfoertner (hugo at pfoertner.org), May 23 2002



 From listed terms I noticed : 1<A071383(n+1)/A071383(n)<=5

And A071383(n+1)/A071383(n) = 5 for some n = 1,2,4,8,12,20 ... ( coincidence
: those first terms are also the first terms of A023598). Are there other
values of n with this property?

Is there any value of n such that A071383(n+1)/A071383(n)>5 ?

About the asymptotic behaviour of A071383 :

Does lim n-->infinity Log(A071383(n))/n = 1 ?


Benoit Cloitre  abcloitre at wanadoo.fr