|
%I #12 Feb 19 2023 11:16:17
%S 0,1,0,-1,0,1,2,1,0,-1,-2,-1,-2,-1,0,-1,0,1,2,1,2,3,2,1,2,1,0,-1,-2,
%T -1,0,1,0,-1,-2,-3,-4,-3,-2,-3,-4,-3,-4,-3,-2,-3,-2,-1,-2,-1,0,-1,0,1,
%U 2,3,4,5,4,3,2,1,0,1,0,1,2,1,2,3,4,3,4,3,2,3,2,1
%N Partial sums of A360710.
%H Rémy Sigrist, <a href="/A360711/b360711.txt">Table of n, a(n) for n = 0..10000</a>
%H Rémy Sigrist, <a href="/A360711/a360711.png">Scatterplot of (log(n), sign(a(n))*log(1+abs(a(n)))) for n <= 2^24</a>
%F a(n) = Sum_{k = 1..n} A360710(k).
%e a(3) = A360710(1) + A360710(2) + A360710(3) = -1 - 1 + 1 = -1.
%o (PARI) { my (s=0, f); for (n=1, #a=vector(78), print1 (s", "); f=factor(n); s+=a[n]=if (#f~==1, if (s, -sign(s), a[n-1]), prod(k=1, #f~, a[f[k, 1]^f[k, 2]]))) }
%Y Cf. A360710.
%K sign,look
%O 0,7
%A _Rémy Sigrist_, Feb 17 2023
|
