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.

Showing 1-2 of 2 results.

A349384 Dirichlet convolution of A003961 with the Dirichlet inverse of A048673, where A003961 is fully multiplicative with a(p) = nextprime(p), and A048673(n) = (1+A003961(n))/2.

Original entry on oeis.org

1, 1, 2, 2, 3, 0, 5, 4, 6, 0, 6, -2, 8, 0, 0, 8, 9, -4, 11, -3, 0, 0, 14, -8, 12, 0, 18, -5, 15, -12, 18, 16, 0, 0, 0, -14, 20, 0, 0, -12, 21, -20, 23, -6, -12, 0, 26, -24, 30, -9, 0, -8, 29, -24, 0, -20, 0, 0, 30, -24, 33, 0, -20, 32, 0, -24, 35, -9, 0, -30, 36, -36, 39, 0, -18, -11, 0, -32, 41, -36, 54, 0, 44
Offset: 1

Views

Author

Antti Karttunen, Nov 17 2021

Keywords

Comments

Convolving this with A336840 gives A003973.

Crossrefs

Cf. A003961, A048673, A323893, A349385 (Dirichlet inverse), A349386 (sum with it).
Cf. also A003973, A336840, A349572.

Programs

Formula

a(n) = Sum_{d|n} A003961(n/d) * A323893(d).
a(n) = A349386(n) - A349385(n).

A349571 Dirichlet convolution of A048673 with A055615 (Dirichlet inverse of n).

Original entry on oeis.org

1, 0, 0, 1, -1, 2, -1, 4, 4, 3, -4, 4, -4, 5, 6, 13, -7, 6, -7, 5, 10, 6, -8, 10, 5, 8, 24, 9, -13, -2, -12, 40, 12, 9, 16, 16, -16, 11, 16, 11, -19, -2, -19, 8, 14, 14, -20, 28, 19, 9, 18, 12, -23, 26, 22, 21, 22, 15, -28, 2, -27, 18, 26, 121, 28, -8, -31, 11, 28, -8, -34, 46, -33, 20, 18, 15, 34, -8, -37, 29, 124
Offset: 1

Views

Author

Antti Karttunen, Nov 23 2021

Keywords

Comments

Also Dirichlet convolution of A349385 with A349387.

Crossrefs

Cf. A048673, A055615, A349385, A349387, A349572 (Dirichlet inverse).
Cf. also A349398, A349573.

Programs

  • Mathematica
    f[p_, e_] := NextPrime[p]^e; s[1] = 1; s[n_] := (1 + Times @@ f @@@ FactorInteger[n])/2; a[n_] := DivisorSum[n, # * MoebiusMu[#] * s[n/#] &]; Array[a, 100] (* Amiram Eldar, Nov 23 2021 *)
  • PARI
    A048673(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); (1/2)*(1+factorback(f)); };
    A055615(n) = (n*moebius(n));
    A349571(n) = sumdiv(n,d,A048673(n/d)*A055615(d));

Formula

a(n) = Sum_{d|n} A048673(n/d) * A055615(d).
a(n) = Sum_{d|n} A349385(n/d) * A349387(d).
Showing 1-2 of 2 results.