cp's OEIS Frontend

A324336 a(n) = A323893(A005940(1+n)).

%I A324336 #6 Feb 24 2019 01:59:27
%S A324336 1,-2,-3,-1,-4,4,-4,-2,-6,5,6,3,-9,8,-12,-4,-7,7,8,4,9,5,16,8,-25,18,
%T A324336 27,8,-36,32,-36,-8,-9,8,9,6,10,11,24,11,12,20,49,6,54,4,72,20,-36,50,
%U A324336 75,18,100,0,72,16,-150,99,162,24,-144,120,-108,-16,-10,10,11,7,12,14,28,17,14,25,60,12,63,12,112,28,15,47,106,21,165,-110,84,-5
%N A324336 a(n) = A323893(A005940(1+n)).
%H A324336 Antti Karttunen, <a href="/A324336/b324336.txt">Table of n, a(n) for n = 0..8192</a>
%H A324336 Antti Karttunen, <a href="/A324336/a324336.txt">Data supplement: n, a(n) computed for n = 0..65537</a>
%H A324336 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%H A324336 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>
%F A324336 a(n) = A323893(A005940(1+n)).
%o A324336 (PARI)
%o A324336 A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t }; \\ From A005940
%o A324336 A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); \\ From A003961
%o A324336 A048673(n) = (A003961(n)+1)/2;
%o A324336 memoA323893 = Map();
%o A324336 A323893(n) = if(1==n,1,my(v); if(mapisdefined(memoA323893,n,&v), v, v = -sumdiv(n,d,if(d<n,A048673(n/d)*A323893(d),0)); mapput(memoA323893,n,v); (v)));
%o A324336 A324336(n) = A323893(A005940(1+n));
%Y A324336 Cf. A003961, A005940, A048673, A323893, A323915, A324335.
%K A324336 sign
%O A324336 0,2
%A A324336 _Antti Karttunen_, Feb 23 2019