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 1-5 of 5 results.

A378528 Dirichlet inverse of A378444.

Original entry on oeis.org

1, -1, -1, 0, -1, 1, -1, 0, -1, 1, -1, -1, -1, 1, 0, -1, -1, 1, -1, -1, 0, 1, -1, 1, -1, 1, 1, -1, -1, 0, -1, 1, 0, 1, 0, 1, -1, 1, 0, 1, -1, 0, -1, -1, 2, 1, -1, 1, -1, 1, 0, -1, -1, -1, 0, 1, 0, 1, -1, 2, -1, 1, 2, 0, 0, 0, -1, -1, 0, 0, -1, -1, -1, 1, 2, -1, 0, 0, -1, 1, 0, 1, -1, 2, 0, 1, 0, 1, -1, -2, 0, -1, 0, 1, 0, -1, -1, 1, 2, 1, -1, 0, -1, 1, 2
Offset: 1

Views

Author

Antti Karttunen, Dec 01 2024

Keywords

Crossrefs

Möbius transform of A369974.

Programs

Formula

a(1) = 1, and for n > 1, a(n) = -Sum_{d|n, dA378444(n/d) * a(d).
a(n) = Sum_{d|n} A000010(n/d)*A378527(d).
a(n) = Sum_{d|n} A008683(n/d)*A369974(d).

A378546 a(n) is the sum of the divisors d of n for which A083345(n/d) is even, where A083345(n) is the numerator of Sum(e/p: n=Product(p^e)).

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 10, 10, 11, 13, 13, 14, 16, 17, 17, 20, 19, 21, 22, 22, 23, 26, 26, 26, 30, 29, 29, 32, 31, 34, 34, 34, 36, 43, 37, 38, 40, 42, 41, 44, 43, 45, 53, 46, 47, 55, 50, 52, 52, 53, 53, 60, 56, 58, 58, 58, 59, 72, 61, 62, 73, 68, 66, 68, 67, 69, 70, 72, 71, 86, 73, 74, 83, 77, 78, 80, 79, 89, 91
Offset: 1

Views

Author

Antti Karttunen, Nov 30 2024

Keywords

Comments

Dirichlet convolution of A000027 with A369001.
Dirichlet convolution of A000010 (Euler phi) with A378444.

Crossrefs

Programs

Formula

a(n) = Sum_{d|n} A369001(n/d)*d.
a(n) = Sum_{d|n} A000010(n/d)*A378444(d).
a(n) = A000203(n) - A378547(n).

A378445 a(n) is the number of divisors d of n such that A083345(d) is odd, where A083345(n) is the numerator of Sum(e/p: n=Product(p^e)).

Original entry on oeis.org

0, 1, 1, 2, 1, 3, 1, 3, 1, 3, 1, 4, 1, 3, 2, 3, 1, 4, 1, 4, 2, 3, 1, 6, 1, 3, 2, 4, 1, 6, 1, 4, 2, 3, 2, 6, 1, 3, 2, 6, 1, 6, 1, 4, 3, 3, 1, 7, 1, 4, 2, 4, 1, 6, 2, 6, 2, 3, 1, 8, 1, 3, 3, 5, 2, 6, 1, 4, 2, 6, 1, 9, 1, 3, 3, 4, 2, 6, 1, 7, 2, 3, 1, 8, 2, 3, 2, 6, 1, 9, 2, 4, 2, 3, 2, 9, 1, 4, 3, 6, 1, 6, 1, 6, 4
Offset: 1

Views

Author

Antti Karttunen, Nov 27 2024

Keywords

Comments

Number of terms of A369003 that divide n.

Crossrefs

Inverse Möbius transform of A377874.
Cf. also A174273, A378443.

Programs

  • PARI
    A377874(n) = { my(f=factor(n)); (numerator(vecsum(vector(#f~, i, f[i, 2]/f[i, 1])))%2); };
    A378445(n) = sumdiv(n,d,A377874(d));

Formula

a(n) = Sum_{d|n} A377874(d).
a(n) = A000005(n) - A378444(n).

A378544 a(n) is the sum of those divisors d of n for which A083345(d) is even, where A083345(n) is the numerator of Sum(e/p: n=Product(p^e)).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 10, 1, 1, 13, 1, 1, 16, 17, 1, 10, 1, 21, 22, 1, 1, 13, 26, 1, 10, 29, 1, 16, 1, 17, 34, 1, 36, 22, 1, 1, 40, 21, 1, 22, 1, 45, 25, 1, 1, 29, 50, 26, 52, 53, 1, 10, 56, 29, 58, 1, 1, 48, 1, 1, 31, 17, 66, 34, 1, 69, 70, 36, 1, 22, 1, 1, 41, 77, 78, 40, 1, 37, 91, 1, 1, 62, 86, 1, 88, 45, 1, 25
Offset: 1

Views

Author

Antti Karttunen, Nov 29 2024

Keywords

Crossrefs

Cf. also A378444 (number of such divisors).

Programs

Formula

a(n) = Sum_{d|n} d*A369001(d).
a(n) = A000203(n) - A378545(n).

A378443 Inverse Möbius transform of A372573.

Original entry on oeis.org

1, 1, 1, 1, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 2, 2, 2, 2, 4, 2, 2, 2, 2, 4, 3, 2, 2, 2, 4, 2, 4, 2, 2, 2, 2, 2, 4, 3, 3, 2, 2, 2, 3, 4, 4, 2, 2, 2, 4, 2, 2, 2, 3, 4, 4, 2, 2, 2, 4, 2, 4, 2, 2, 3, 2, 4, 4, 2, 4, 2, 2, 2, 4, 4, 2, 2, 4, 2, 4, 4, 2, 2, 2, 4, 4, 2, 3, 2, 3, 2, 4, 2, 4, 4
Offset: 1

Views

Author

Antti Karttunen, Nov 27 2024

Keywords

Comments

Number of terms of A339746 that divide n.

Crossrefs

Cf. also A174273, A378444.

Programs

Formula

a(n) = Sum_{d|n} A372573(d).
Showing 1-5 of 5 results.