cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A364574 Dirichlet inverse of A005941.

Original entry on oeis.org

1, -2, -3, 0, -5, 6, -9, 0, 2, 10, -17, 0, -33, 18, 19, 0, -65, -4, -129, 0, 35, 34, -257, 0, 12, 66, 0, 0, -513, -38, -1025, 0, 67, 130, 69, 0, -2049, 258, 131, 0, -4097, -70, -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
Offset: 1

Views

Author

Antti Karttunen, Aug 05 2023

Keywords

Crossrefs

Cf. also A324640.

Programs

  • PARI
    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)
    memoA364574 = Map();
    A364574(n) = if(1==n,1,my(v); if(mapisdefined(memoA364574,n,&v), v, v = -sumdiv(n,d,if(dA005941(n/d)*A364574(d),0)); mapput(memoA364574,n,v); (v)));

Formula

a(1) = 1, and for n > 1, a(n) = -Sum_{d|n, dA005941(n/d) * a(d).
a(p) = -A005941(p) for all primes p.

A364953 a(n) = A364952(A005940(1+n)), where A364952 is Dirichlet inverse of A364557, which is Möbius transform of A005941 [the inverse permutation of A005940].

Original entry on oeis.org

1, -1, -2, -1, -4, 2, 0, -1, -8, 4, 12, 2, 8, 0, 0, -1, -16, 8, 24, 4, 56, -12, -8, 2, 48, -8, -40, 0, -16, 0, 0, -1, -32, 16, 48, 8, 112, -24, -16, 4, 240, -56, -232, -12, -208, 8, 0, 2, 224, -48, -208, -8, -528, 40, 64, 0, -288, 16, 112, 0, 32, 0, 0, -1, -64, 32, 96, 16, 224, -48, -32, 8, 480, -112, -464, -24
Offset: 0

Views

Author

Antti Karttunen, Aug 29 2023

Keywords

Crossrefs

Programs

  • PARI
    A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t };
    A364557(n) = if(1==n, 1, 2^(primepi(vecmax(factor(n)[, 1]))+(bigomega(n)-omega(n))-1));
    memoA364952 = Map();
    A364952(n) = if(1==n,1,my(v); if(mapisdefined(memoA364952,n,&v), v, v = -sumdiv(n,d,if(dA364557(n/d)*A364952(d),0)); mapput(memoA364952,n,v); (v)));
    A364953(n) = A364952(A005940(1+n));
Showing 1-2 of 2 results.