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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A349613 Dirichlet convolution of A064413 (EKG-permutation) with the Dirichlet inverse of its inverse permutation.

Original entry on oeis.org

1, 0, -1, 3, -7, 7, -2, -6, 9, 10, -5, -15, -14, -2, 55, 10, -17, -41, -15, -36, 42, 18, -13, 44, 81, 29, -35, -45, -18, -180, -29, -23, 41, 53, 135, 99, -48, 51, 114, 131, -30, -140, -58, -53, -303, 34, -37, -120, 34, -196, 147, -87, -45, 226, 207, 166, 103, 67, -41, 466, -84, 91, -288, 13, 350, -258, -91, -108
Offset: 1

Views

Author

Antti Karttunen, Nov 23 2021

Keywords

Comments

Obviously, convolving this with A064664 gives A064413 back.

Crossrefs

Cf. A064413, A064664, A323411, A349614 (Dirichlet inverse), A349615 (sum with it), A349616.
Cf. also pairs A349376, A349377 and A349397, A349398 for similar constructions.

Programs

  • PARI
    up_to = 32768;
    v064413 = readvec("b064413_upto65539_terms_only.txt"); \\ Data prepared with Chai Wah Wu's Dec 08 2014 Python-program given in A064413.
    A064413(n) = v064413[n];
    \\ Then its inverse A064664 is prepared:
    m064664 = Map();
    for(n=1,65539,mapput(m064664,A064413(n),n));
    A064664(n) = mapget(m064664,n);
    DirInverseCorrect(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = (-u[1]*sumdiv(n, d, if(dA064664(n)));
    A323411(n) = v323411[n];
    A349613(n) = sumdiv(n,d,A064413(d)*A323411(n/d));

Formula

a(n) = Sum_{d|n} A064413(d) * A323411(n/d).

A349617 Dirichlet convolution of A064664 (the inverse permutation of EKG-permutation) with A055615 (Dirichlet inverse of n).

Original entry on oeis.org

1, 0, 2, -1, 5, -6, 7, 2, -9, -11, 9, 2, 15, -15, -29, 1, 16, 18, 18, 5, -41, -21, 20, -4, -26, -29, 4, 7, 28, 64, 30, -3, -61, -34, -80, 9, 30, -38, -81, -6, 33, 92, 38, 14, 51, -44, 42, 10, -48, 53, -99, 6, 47, 4, -102, -17, -111, -58, 48, -4, 54, -62, 69, 2, -151, 146, 61, 18, -131, 157, 63, -3, 65, -68, 92, 18
Offset: 1

Views

Author

Antti Karttunen, Nov 23 2021

Keywords

Comments

Dirichlet convolution of this sequence with A000010 (Euler phi) is A304526 (Möbius transform of the inverse permutation of EKG-sequence).

Crossrefs

Cf. A055615, A064413, A064664, A349616 (Dirichlet inverse).
Cf. also A000010, A304526, A349614.

Programs

  • PARI
    A055615(n) = (n*moebius(n));
    v064413 = readvec("b064413_upto65539_terms_only.txt"); \\ Data prepared with Chai Wah Wu's Dec 08 2014 Python-program given in A064413.
    A064413(n) = v064413[n];
    \\ Then its inverse A064664 is prepared:
    m064664 = Map();
    for(n=1,65539,mapput(m064664,A064413(n),n));
    A064664(n) = mapget(m064664,n);
    A349617(n) = sumdiv(n,d,A064664(d)*A055615(n/d));

Formula

a(n) = Sum_{d|n} A064664(d) * A055615(n/d).
Showing 1-2 of 2 results.