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.

A340190 Möbius transform of A063994(x) = Product_{primes p dividing x} gcd(p-1, x-1).

Original entry on oeis.org

1, 0, 1, 0, 3, -1, 5, 0, 0, -3, 9, 0, 11, -5, -1, 0, 15, 0, 17, 0, -3, -9, 21, 0, 0, -11, 0, 2, 27, 1, 29, 0, -7, -15, -5, 0, 35, -17, -9, 0, 39, 3, 41, 0, 4, -21, 45, 0, 0, 0, -13, 2, 51, 0, -9, -2, -15, -27, 57, 0, 59, -29, 0, 0, 1, 11, 65, 0, -19, 7, 69, 0, 71, -35, 0, 2, -11, 9, 77, 0, 0, -39, 81, -2, -3, -41, -25
Offset: 1

Views

Author

Antti Karttunen, Dec 31 2020

Keywords

Crossrefs

Programs

  • PARI
    A063994(n) = { my(f=factor(n)); prod(i=1, #f~, gcd(f[i, 1]-1, n-1)); };
    A340190(n) = sumdiv(n,d,moebius(n/d)*A063994(d));

Formula

a(n) = Sum_{d|n} A008683(n/d) * A063994(d).
a(n) = A063994(n) - A340191(n).

A340193 a(n) = n - (Sum_{d|n} A063994(d)).

Original entry on oeis.org

0, 0, 0, 1, 0, 1, 0, 4, 4, 3, 0, 5, 0, 5, 4, 11, 0, 10, 0, 11, 8, 9, 0, 15, 16, 11, 20, 15, 0, 15, 0, 26, 16, 15, 20, 25, 0, 17, 20, 29, 0, 25, 0, 29, 24, 21, 0, 37, 36, 38, 28, 33, 0, 43, 36, 41, 32, 27, 0, 41, 0, 29, 44, 57, 32, 41, 0, 47, 40, 49, 0, 58, 0, 35, 56, 51, 56, 55, 0, 67, 72, 39, 0, 61, 48, 41, 52, 71, 0, 63, 36
Offset: 1

Views

Author

Antti Karttunen, Dec 31 2020

Keywords

Crossrefs

Inverse Möbius transform of A318840.
Cf. also A051953.

Programs

  • PARI
    A063994(n) = { my(f=factor(n)); prod(i=1, #f~, gcd(f[i, 1]-1, n-1)); };
    A340193(n) = (n-sumdiv(n,d,A063994(d)));

Formula

a(n) = n - A340192(n).
a(n) = Sum_{d|n} A318840(d).

A340195 a(n) = Sum_{divisors d of n} A049559(d), where A049559(x) = gcd(phi(x), x-1).

Original entry on oeis.org

1, 2, 3, 3, 5, 5, 7, 4, 5, 7, 11, 7, 13, 9, 9, 5, 17, 8, 19, 9, 13, 13, 23, 9, 9, 15, 7, 13, 29, 13, 31, 6, 17, 19, 13, 11, 37, 21, 17, 11, 41, 17, 43, 15, 15, 25, 47, 11, 13, 12, 21, 19, 53, 11, 17, 15, 25, 31, 59, 17, 61, 33, 17, 7, 33, 25, 67, 21, 29, 19, 71, 14, 73, 39, 15, 25, 21, 21, 79, 13, 9, 43, 83, 23, 25, 45, 33
Offset: 1

Views

Author

Antti Karttunen, Jan 02 2021

Keywords

Crossrefs

Inverse Möbius transform of A049559.
Cf. also A340192.

Programs

Formula

a(n) = Sum_{d|n} A049559(d).
a(n) = n - A340196(n).
Showing 1-3 of 3 results.