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.

A326060 a(n) = gcd(n-A035316(n), A285309(n)-n), where A035316 and A285309 give respectively the sums of square and nonsquare divisors of n.

Original entry on oeis.org

1, 1, 2, 1, 4, 5, 6, 1, 1, 1, 10, 1, 12, 1, 2, 1, 16, 1, 18, 1, 10, 1, 22, 1, 1, 5, 1, 23, 28, 1, 30, 1, 2, 1, 2, 1, 36, 1, 2, 5, 40, 1, 42, 1, 1, 5, 46, 1, 1, 1, 10, 1, 52, 4, 2, 1, 2, 1, 58, 1, 60, 1, 1, 1, 2, 1, 66, 1, 2, 1, 70, 1, 72, 1, 1, 1, 2, 1, 78, 1, 1, 1, 82, 1, 2, 5, 2, 1, 88, 2, 10, 1, 2, 1, 2, 15, 96, 1, 1, 1, 100, 1, 102, 1, 2
Offset: 1

Views

Author

Antti Karttunen, Jun 06 2019

Keywords

Comments

Below 2^27 there are following numbers k such that a(k) is equal to A326059(k), and quotient A326058(k)/A326059(k) is odd: 6, 28, 496, 1625, 2057, 8128, 33550336, 107452235. The odd terms are factored as: 1625 = 5^3 * 13, 2057 = 11^2 * 17, 107452235 = 5 * 11^2 * 97 * 1831.

Crossrefs

Programs

Formula

a(n) = gcd(A326058(n), A326059(n)) = gcd(n-A035316(n), A285309(n)-n).

A326059 a(n) = A285309(n) - n, where A285309 gives the sum of nonsquare divisors of n.

Original entry on oeis.org

-1, 0, 0, -2, 0, 5, 0, 2, -6, 7, 0, 11, 0, 9, 8, -6, 0, 11, 0, 17, 10, 13, 0, 31, -20, 15, 3, 23, 0, 41, 0, 10, 14, 19, 12, 5, 0, 21, 16, 45, 0, 53, 0, 35, 23, 25, 0, 55, -42, 17, 20, 41, 0, 56, 16, 59, 22, 31, 0, 103, 0, 33, 31, -22, 18, 77, 0, 53, 26, 73, 0, 73, 0, 39, 23, 59, 18, 89, 0, 85, -51, 43, 0, 135, 22, 45, 32, 87, 0, 134, 20
Offset: 1

Views

Author

Antti Karttunen, Jun 06 2019

Keywords

Crossrefs

Programs

Formula

a(n) = A285309(n) - n.
a(n) = A326058(n) - A033879(n).

A326053 Sum of all other divisors of n except the largest square divisor: a(n) = sigma(n) - A008833(n).

Original entry on oeis.org

0, 2, 3, 3, 5, 11, 7, 11, 4, 17, 11, 24, 13, 23, 23, 15, 17, 30, 19, 38, 31, 35, 23, 56, 6, 41, 31, 52, 29, 71, 31, 47, 47, 53, 47, 55, 37, 59, 55, 86, 41, 95, 43, 80, 69, 71, 47, 108, 8, 68, 71, 94, 53, 111, 71, 116, 79, 89, 59, 164, 61, 95, 95, 63, 83, 143, 67, 122, 95, 143, 71, 159, 73, 113, 99, 136, 95, 167, 79, 170, 40, 125, 83
Offset: 1

Views

Author

Antti Karttunen, Jun 05 2019

Keywords

Crossrefs

Programs

Formula

a(n) = A000203(n) - A008833(n).
a(n) = n + A326054(n).
a(n) >= A285309(n).
Showing 1-3 of 3 results.