A242620 - cp's OEIS frontend

A242620 a(n) is the largest number in the interval (1, 2^(2^(n-1))) that is a member of a pair of integers the sum of whose squares is equal to the Fermat number 2^(2^n) + 1, or 0 if no such number exists.

%I A242620 #10 May 21 2014 20:58:16
%S A242620 0,0,0,0,0,62264,4046803256,16382350221535464479,
%T A242620 339840244399005511779394711120340266111
%N A242620 a(n) is the largest number in the interval (1, 2^(2^(n-1))) that is a member of a pair of integers the sum of whose squares is equal to the Fermat number 2^(2^n) + 1, or 0 if no such number exists.
%C A242620 2^(2^n) + 1 belongs to A019434 if and only if a(n) = 0.
%H A242620 Wikipedia, <a href="http://en.wikipedia.org/wiki/Fermat_number">Fermat number</a>
%Y A242620 Cf. A000215, A242619.
%K A242620 nonn
%O A242620 0,6
%A A242620 _Arkadiusz Wesolowski_, May 19 2014

cp's OEIS Frontend

A242620 a(n) is the largest number in the interval (1, 2^(2^(n-1))) that is a member of a pair of integers the sum of whose squares is equal to the Fermat number 2^(2^n) + 1, or 0 if no such number exists.