A353459 Sum of A353457 and its Dirichlet inverse.
2, 0, 0, 1, 0, -2, 0, 1, 1, 2, 0, -1, 0, -2, -2, 1, 0, -1, 0, 1, 2, 2, 0, -1, 1, -2, 1, -1, 0, 0, 0, 1, -2, 2, -2, 0, 0, -2, 2, 1, 0, 0, 0, 1, -1, 2, 0, -1, 1, 1, -2, -1, 0, -1, 2, -1, 2, -2, 0, -1, 0, 2, 1, 1, -2, 0, 0, 1, -2, 0, 0, 0, 0, -2, -1, -1, -2, 0, 0, 1, 1, 2, 0, 1, 2, -2, 2, 1, 0, 1, 2, 1, -2, 2, -2, -1, 0
Offset: 1
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Programs
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PARI
A000265(n) = (n>>valuation(n,2)); A064989(n) = { my(f=factor(A000265(n))); for(i=1, #f~, f[i,1] = precprime(f[i,1]-1)); factorback(f); }; memoA353457 = Map(); A353457(n) = if(1==n,1,my(v); if(mapisdefined(memoA353457,n,&v), v, v = -sumdiv(n,d,if(d
A353457(A064989(n/d))*A353457(d),0)); mapput(memoA353457,n,v); (v))); A353459(n) = (A353457(n)+A353457(A064989(n))); -
Python
from math import prod from sympy import factorint, primepi def A353459(n): f = [(primepi(p)&1, -int(e==1)) for p, e in factorint(n).items()] return prod(e for p, e in f if not p)+prod(e for p, e in f if p) # Chai Wah Wu, Jan 05 2023
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