cp's OEIS Frontend

A373896 Number of lattice points inside or on the 8-dimensional hypersphere x_1^2 + x_2^2 + x_3^2 + x_4^2 + x_5^2 + x_6^2 + x_7^2 + x_8^2 = 10^n.

%I A373896 #14 Jun 21 2024 10:47:19
%S A373896 17,47921,415055025,4068011664081,40596481219349025,
%T A373896 405880555110153633585,4058721509888208894731345,
%U A373896 40587130610718907618215585345,405871222004868007901459647593809,4058712135741827985063748936303681217
%N A373896 Number of lattice points inside or on the 8-dimensional hypersphere x_1^2 + x_2^2 + x_3^2 + x_4^2 + x_5^2 + x_6^2 + x_7^2 + x_8^2 = 10^n.
%F A373896 a(n) = A341397(10^n).
%F A373896 a(n) == 1 (mod 16).
%o A373896 (PARI) a008457(n) = sumdiv(n, d, (-1)^(n-d)*d^3);
%o A373896 a341397(n) = 1+16*sum(k=1, n, a008457(k));
%o A373896 a(n) = a341397(10^n);
%Y A373896 Cf. A068785, A373881, A373882, A373883, A373884, A373885.
%Y A373896 Cf. A008457, A341397.
%K A373896 nonn
%O A373896 0,1
%A A373896 _Seiichi Manyama_, Jun 21 2024