A368700 - OEIS

%I #8 Jan 12 2024 12:05:03

%S 0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,2,2,3,4,4,4,4,4,4,4,4,4,4,4,

%T 5,6,6,6,7,7,7,8,8,9,9,9,10,10,10,10,10,10,11,11,11,11,11,11,12,13,13,

%U 13,13,13,13,13,13,14,14,15,16,16,17,17,17,17,17,17,18,18,19,19,20,21,22,22,23,24,25,25,26

%N Partial sums of A368699.

%H Antti Karttunen, <a href="/A368700/b368700.txt">Table of n, a(n) for n = 0..16384</a>

%o (PARI)

%o up_to = 1024;

%o A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); (t); };

%o A354989(n) = for(m=1, oo, if((m*(m+1))%n==0, return(gcd(n, 1+m)<gcd(n, m))));

%o A368699(n) = A354989(A005940(1+n));

%o A368700list(up_to) = { my(v=vector(up_to), s=A368699(0)); for(i=1, up_to, s += A368699(i); v[i] = s); (v); };

%o v368700 = A368700list(up_to);

%o A368700(n) = if(!n, A368699(0), v368700[n]);

%Y Partial sums of A368699.

%Y Cf. A354989, A368698.

%K nonn

%O 0,21

%A _Antti Karttunen_, Jan 11 2024