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A364574 Dirichlet inverse of A005941. 3

%I #9 Aug 05 2023 15:46:43

%S 1,-2,-3,0,-5,6,-9,0,2,10,-17,0,-33,18,19,0,-65,-4,-129,0,35,34,-257,

%T 0,12,66,0,0,-513,-38,-1025,0,67,130,69,0,-2049,258,131,0,-4097,-70,

%U -8193,0,-22,514,-16385,0,56,-24,259,0,-32769,0,133,0,515,1026,-65537,0,-131073,2050,-42,0,261,-134,-262145,0,1027

%N Dirichlet inverse of A005941.

%H Antti Karttunen, <a href="/A364574/b364574.txt">Table of n, a(n) for n = 1..8192</a>

%F a(1) = 1, and for n > 1, a(n) = -Sum_{d|n, d<n} A005941(n/d) * a(d).

%F a(p) = -A005941(p) for all primes p.

%o (PARI)

%o A005941(n) = { my(f=factor(n), p, p2=1, res=0); for(i=1, #f~, p = 1 << (primepi(f[i, 1])-1); res += (p * p2 * (2^(f[i, 2])-1)); p2 <<= f[i, 2]); (1+res) }; \\ (After _David A. Corneth_'s program for A156552)

%o memoA364574 = Map();

%o A364574(n) = if(1==n,1,my(v); if(mapisdefined(memoA364574,n,&v), v, v = -sumdiv(n,d,if(d<n,A005941(n/d)*A364574(d),0)); mapput(memoA364574,n,v); (v)));

%Y Cf. A005941, A364575.

%Y Cf. also A324640.

%K sign

%O 1,2

%A _Antti Karttunen_, Aug 05 2023

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Last modified May 11 19:25 EDT 2024. Contains 372413 sequences. (Running on oeis4.)