cp's OEIS Frontend

A175376 Partial sums of A175375.

%I A175376 #5 May 01 2019 15:32:08
%S A175376 1,7,19,27,27,27,27,27,27,27,27,27,27,27,27,27,33,57,81,81,81,81,81,
%T A175376 81,81,81,81,81,81,81,81,81,93,117,117,117,117,117,117,117,117,117,
%U A175376 117,117,117,117,117,117,125,125,125,125,125,125,125,125,125,125,125,125,125
%N A175376 Partial sums of A175375.
%C A175376 Number of integer triples (x,y,z) satisfying x^4+y^4+z^4 <= n, -n <= x,y,z <= n.
%H A175376 Robert Israel, <a href="/A175376/b175376.txt">Table of n, a(n) for n = 0..10000</a>
%F A175376 G.f.: (1 + 2*Sum_{j>0} x^(j^4))^3/(1-x). - _Robert Israel_, May 01 2019
%p A175376 N:= 100: # to get a(1)..a(N)
%p A175376 A:= Array(0..N):
%p A175376 for i from 0 while i^4 <= N do
%p A175376   if i=0 then ai:= 1 else ai:= 2 fi;
%p A175376   for j from 0 while i^4 + j^4 <= N do
%p A175376     if j=0 then aj:= 1 else aj:= 2 fi;
%p A175376     for k from 0 do
%p A175376       v:= i^4 + j^4 + k^4;
%p A175376       if v > N then break fi;
%p A175376       if k = 0 then ak:= 1 else ak:= 2 fi;
%p A175376       A[v]:= A[v] + ai*aj*ak;
%p A175376 od od od:
%p A175376 ListTools:-PartialSums(convert(A,list)); # _Robert Israel_, May 01 2019
%Y A175376 Cf. A117609, A175366, A175375.
%K A175376 nonn
%O A175376 0,2
%A A175376 _R. J. Mathar_, Apr 24 2010