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 1-3 of 3 results.

A349378 a(n) = A349376(n) + A349377(n).

Original entry on oeis.org

2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, -6, 0, 0, 0, 10, 9, 0, 0, -8, 0, -30, 0, -4, 0, 0, 24, 27, 0, 0, 0, 34, 0, -40, 0, -14, -6, 0, 0, -34, 16, -66, 0, -14, 0, 10, 42, 44, 0, 0, 0, 166, 0, 0, -8, 11, 42, -70, 0, -20, 0, -172, 0, -70, 0, 0, -42, -22, 56, -70, 0, -103, 1, 0, 0, 216, 60, 0, 0, 78
Offset: 1

Views

Author

Antti Karttunen, Nov 17 2021

Keywords

Crossrefs

Programs

Formula

a(1) = 2, and for n >1, a(n) = -Sum_{d|n, 1A349376(d) * A349377(n/d). [As the sequences are Dirichlet inverses of each other]

A349351 Dirichlet inverse of A006368, "the amusical permutation", a(2n)=3n, a(4n+1)=3n+1, a(4n-1)=3n-1.

Original entry on oeis.org

1, -3, -2, 3, -4, 3, -5, -3, -3, 9, -8, 6, -10, 9, 5, 3, -13, 15, -14, 0, 4, 15, -17, -15, -3, 21, 0, 9, -22, 9, -23, -3, 7, 27, 14, -24, -28, 27, 11, -9, -31, 27, -32, 12, 18, 33, -35, 24, -12, 15, 14, 6, -40, 9, 23, -27, 13, 45, -44, -63, -46, 45, 27, 3, 31, 39, -50, 9, 16, 9, -53, 6, -55, 57, 12, 18, 22, 33, -59
Offset: 1

Views

Author

Antti Karttunen, Nov 15 2021

Keywords

Crossrefs

Programs

  • PARI
    up_to = 20000;
    DirInverseCorrect(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = (-u[1]*sumdiv(n, d, if(dA006368(n) = ((3*n)+(n%2))\(2+((n%2)*2));
    v349351 = DirInverseCorrect(vector(up_to,n,A006368(n)));
    A349351(n) = v349351[n];

Formula

a(1) = 1; a(n) = -Sum_{d|n, d < n} A006368(n/d) * a(d).
a(n) = A349352(n) - A006368(n).

A349369 Sum of A006369 and its Dirichlet inverse, where A006369 is the inverse of "amusical permutation", A006368.

Original entry on oeis.org

2, 0, 0, 9, 0, 12, 0, 3, 4, 42, 0, -10, 0, 54, 28, 37, 0, 16, 0, -41, 36, 90, 0, 60, 49, 102, 16, -39, 0, -84, 0, 11, 60, 138, 126, 30, 0, 150, 68, 221, 0, -92, 0, -81, 40, 186, 0, -72, 81, -61, 92, -79, 0, 36, 210, 259, 100, 234, 0, 394, 0, 246, 56, 149, 238, -172, 0, -121, 124, -352, 0, 8, 0, 294, -22, -119, 270
Offset: 1

Views

Author

Antti Karttunen, Nov 17 2021

Keywords

Crossrefs

Cf. also A349352, A349378.

Programs

Formula

a(n) = A006369(n) + A349368(n).
a(1) = 2, and for n >1, a(n) = -Sum_{d|n, 1A006369(d) * A349368(n/d).
Showing 1-3 of 3 results.