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Partial sums of A267326.
2

%I #50 Jan 06 2019 06:07:35

%S 8,32,136,160,408,720,1176,1200,2168,2912,3976,4288,5752,7120,10344,

%T 10368,12824,15728,18776,19520,25448,28640,33064,33376,39624,44016,

%U 52760,54128,61096,70768,78712,78736,92568,99936,114072,116976,128232,137376,156408

%N Partial sums of A267326.

%H Christopher Heiling, <a href="/A264390/b264390.txt">Table of n, a(n) for n = 1..150</a>

%F a(n) = Sum_{k = 1..n} A000118(k^2).

%e For n = 2 the a(n) = 32 integral solutions of x^2 + y^2 + z^2 + t^2 <= 2^2 are: {x,y,z,t} = {{0,0,0,1}; {0,0,1,0}; {0,1,0,0}; {1,0,0,0}; {0,0,0,-1}; {0,0,-1,0}; {0,-1,0,0}; {-1,0,0,0}; {0,0,0,2}; {0,0,0,-2}; {0,0,2,0}; {0,0,-2,0}; {0,2,0,0}; {0,-2,0,0}; {2,0,0,0}; {-2,0,0,0}; {1,1,1,1}; {1,1,1,-1}; {1,1,-1,1}; {1,-1,1,1}; {-1,1,1,1}; {1,1,-1,-1}; {1,-1,1,-1}; {-1,1,1,-1}; {1,-1,-1,1}; {-1,1,-1,1}; {1,-1,-1,-1}; {-1,1,-1,-1}; {-1,-1,1,-1}; {-1,-1,1,-1}; {-1,-1,-1,1}; {-1,-1,-1,-1}}.

%p #A264390

%p terms := 42:

%p (add(q^(m^2), m = -terms..terms))^4:

%p seq(add(coeff(%, q, k^2), k = 1..n), n = 1..terms); # _Peter Bala_, Jan 15 2016

%o (PARI) a000118(k) = if(k<1, k==0, 8 * sumdiv( k, d, if( d%4, d)));

%o a(n) = sum(k=1, n, a000118(k^2)); \\ _Altug Alkan_, Jan 19 2016

%Y Partial sums of A267326.

%Y Cf. A000118, A046897.

%K nonn,easy

%O 1,1

%A _Christopher Heiling_, Jan 12 2016