%I #15 Jul 18 2018 02:19:19

%S 1,4,9,20,25,36,49,112,99,100,121,180,169,196,225,704,289,396,361,500,

%T 441,484,529,1008,725,676,1377,980,589,900,961,4864,1089,1156,1225,

%U 1980,1369,1444,1521,2800,1681,1764,4999,2420,2475,2116,2209,6336,10633,2900

%N Number of solutions to x^7 + y^7 = z^7 mod n.

%C Equivalently, the number of solutions to x^7 + y^7 + z^7 == 0 (mod n). - _Andrew Howroyd_, Jul 17 2018

%H Seiichi Manyama, <a href="/A288102/b288102.txt">Table of n, a(n) for n = 1..1000</a>

%o (PARI) a(n)={my(p=Mod(sum(i=0, n-1, x^lift(Mod(i,n)^7)), 1-x^n)); polcoeff(lift(p^3), 0)} \\ _Andrew Howroyd_, Jul 17 2018

%Y Number of solutions to x^k + y^k = z^k mod n: A062775 (k=2), A063454 (k=3), A288099 (k=4), A288100 (k=5), A288101 (k=6), this sequence (k=7), A288103 (k=8), A288104 (k=9), A288105 (k=10).

%K nonn,mult

%O 1,2

%A _Seiichi Manyama_, Jun 05 2017

%E Keyword:mult added by _Andrew Howroyd_, Jul 17 2018