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 1-10 of 28 results. Next

A318828 a(n) = n - A063994(n) = n - Product_{primes p dividing n} gcd(p-1, n-1).

Original entry on oeis.org

0, 1, 1, 3, 1, 5, 1, 7, 7, 9, 1, 11, 1, 13, 11, 15, 1, 17, 1, 19, 17, 21, 1, 23, 21, 25, 25, 25, 1, 29, 1, 31, 29, 33, 31, 35, 1, 37, 35, 39, 1, 41, 1, 43, 37, 45, 1, 47, 43, 49, 47, 49, 1, 53, 51, 55, 53, 57, 1, 59, 1, 61, 59, 63, 49, 61, 1, 67, 65, 67, 1, 71, 1, 73, 71, 73, 73, 77, 1, 79, 79, 81, 1, 83, 69, 85, 83, 87, 1, 89, 55
Offset: 1

Views

Author

Antti Karttunen, Sep 09 2018

Keywords

Crossrefs

Programs

Formula

a(n) = n - A063994(n).

A323405 Lexicographically earliest sequence such that for all i, j, a(i) = a(j) => f(i) = f(j) where f(n) = [A003557(n), A023900(n), A063994(n)] for all other numbers, except f(n) = 0 for odd primes.

Original entry on oeis.org

1, 2, 3, 4, 3, 5, 3, 6, 7, 8, 3, 9, 3, 10, 11, 12, 3, 13, 3, 14, 15, 16, 3, 17, 18, 19, 20, 21, 3, 22, 3, 23, 24, 25, 26, 27, 3, 28, 26, 29, 3, 30, 3, 31, 32, 33, 3, 34, 35, 36, 37, 38, 3, 39, 40, 41, 42, 43, 3, 44, 3, 45, 46, 47, 48, 49, 3, 50, 51, 52, 3, 53, 3, 54, 55, 56, 57, 58, 3, 59, 60, 61, 3, 62, 63, 64, 65, 66, 3, 67, 68, 69, 57, 70, 71, 72, 3, 73, 74, 75, 3
Offset: 1

Views

Author

Antti Karttunen, Jan 13 2019

Keywords

Comments

For all i, j:
A305801(i) = A305801(j) => a(i) = a(j),
a(i) = a(j) => A323371(i) = A323371(j),
a(i) = a(j) => A247074(i) = A247074(j).

Crossrefs

Differs from A323370 for the first time at n=78, where a(78) = 58, while A323370(78) = 52.
Cf. also A323374.

Programs

  • PARI
    up_to = 65537;
    rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };
    A003557(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 2] = max(0,f[i, 2]-1)); factorback(f); };
    A023900(n) = sumdivmult(n, d, d*moebius(d)); \\ From A023900
    A063994(n) = { my(f=factor(n)[, 1]); prod(i=1, #f, gcd(f[i]-1, n-1)); }; \\ From A063994
    Aux323405(n) = if((n>2)&&isprime(n),0,[A003557(n), A023900(n), A063994(n)]);
    v323405 = rgs_transform(vector(up_to, n, Aux323405(n)));
    A323405(n) = v323405[n];

A318829 a(n) = A063994(n) / A049559(n) = (1/gcd(n-1, phi(n))) * Product_{primes p dividing n} gcd(p-1, n-1).

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Sep 09 2018

Keywords

Comments

Records occur at: 1, 15, 85, 247, 671, 949, 1105, 1387, 2047, 2821, 9471, 11305, 13747, 13981, 29341, 40885, 51319, 63973, ...

Crossrefs

Programs

Formula

a(n) = A063994(n) / A049559(n).
a(n) = A160595(n) / A247074(n).

A323404 Lexicographically earliest sequence such that for all i, j, a(i) = a(j) => f(i) = f(j) where f(n) = [A003557(n), A023900(n), A063994(n)].

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 35, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 76, 92
Offset: 1

Views

Author

Antti Karttunen, Jan 13 2019

Keywords

Comments

For all i, j: a(i) = a(j) => A247074(i) = A247074(j).

Crossrefs

Programs

  • PARI
    up_to = 65537;
    rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };
    A003557(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 2] = max(0,f[i, 2]-1)); factorback(f); };
    A023900(n) = sumdivmult(n, d, d*moebius(d)); \\ From A023900
    A063994(n) = { my(f=factor(n)[, 1]); prod(i=1, #f, gcd(f[i]-1, n-1)); }; \\ From A063994
    Aux323404(n) = if(1,[A003557(n), A023900(n), A063994(n)]);
    v323404 = rgs_transform(vector(up_to, n, Aux323404(n)));
    A323404(n) = v323404[n];

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).

A340192 a(n) = Sum_{d|n} A063994(d), where A063994(x) = Product_{primes p dividing x} gcd(p-1, x-1).

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Dec 31 2020

Keywords

Crossrefs

Inverse Möbius transform of A063994.

Programs

  • PARI
    A063994(n) = { my(f=factor(n)); prod(i=1, #f~, gcd(f[i, 1]-1, n-1)); };
    A340192(n) = sumdiv(n,d,A063994(d));

Formula

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

A340187 Dirichlet inverse of A063994(x) = Product_{primes p dividing x} gcd(p-1, x-1).

Original entry on oeis.org

1, -1, -2, 0, -4, 3, -6, 0, 2, 7, -10, -1, -12, 11, 12, 0, -16, -5, -18, -3, 20, 19, -22, 0, 12, 23, -2, -7, -28, -29, -30, 0, 36, 31, 44, 4, -36, 35, 44, 0, -40, -49, -42, -9, -24, 43, -46, 0, 30, -33, 60, -13, -52, 7, 76, 4, 68, 55, -58, 23, -60, 59, -36, 0, 80, -93, -66, -15, 84, -119, -70, -1, -72, 71, -52, -19
Offset: 1

Views

Author

Antti Karttunen, Dec 31 2020

Keywords

Crossrefs

Programs

  • PARI
    up_to = 65537;
    A063994(n) = { my(f=factor(n)); prod(i=1, #f~, gcd(f[i, 1]-1, n-1)); };
    DirInverse(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = -sumdiv(n, d, if(dA063994(n)));
    A340187(n) = v340187[n];

A340188 Sum of A063994 and its Dirichlet inverse, where A063994(x) = Product_{primes p dividing x} gcd(p-1, x-1).

Original entry on oeis.org

2, 0, 0, 1, 0, 4, 0, 1, 4, 8, 0, 0, 0, 12, 16, 1, 0, -4, 0, -2, 24, 20, 0, 1, 16, 24, 0, -4, 0, -28, 0, 1, 40, 32, 48, 5, 0, 36, 48, 1, 0, -48, 0, -8, -16, 44, 0, 1, 36, -32, 64, -10, 0, 8, 80, 5, 72, 56, 0, 24, 0, 60, -32, 1, 96, -88, 0, -14, 88, -116, 0, 0, 0, 72, -48, -16, 120, -108, 0, 1, 4, 80, 0, 48, 128, 84, 112
Offset: 1

Views

Author

Antti Karttunen, Dec 31 2020

Keywords

Crossrefs

Programs

  • PARI
    up_to = 65537;
    A063994(n) = { my(f=factor(n)); prod(i=1, #f~, gcd(f[i, 1]-1, n-1)); };
    DirInverse(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = -sumdiv(n, d, if(dA063994(n)));
    A340187(n) = v340187[n];
    A340188(n) = (A063994(n)+A340187(n));

Formula

a(n) = A063994(n) + A340187(n).
a(n) = A340189(n) - A318828(n).

A340191 Difference between A063994 and its Möbius transform.

Original entry on oeis.org

0, 1, 1, 1, 1, 2, 1, 1, 2, 4, 1, 1, 1, 6, 5, 1, 1, 1, 1, 1, 7, 10, 1, 1, 4, 12, 2, 1, 1, 0, 1, 1, 11, 16, 9, 1, 1, 18, 13, 1, 1, -2, 1, 1, 4, 22, 1, 1, 6, 1, 17, 1, 1, 1, 13, 3, 19, 28, 1, 1, 1, 30, 4, 1, 15, -6, 1, 1, 23, -4, 1, 1, 1, 36, 4, 1, 15, -8, 1, 1, 2, 40, 1, 3, 19, 42, 29, 1, 1, 5, 17, 1, 31, 46, 21
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)); };
    A340191(n) = -sumdiv(n,d,(dA063994(d));

Formula

a(n) = A063994(n) - A340190(n).
a(n) = -Sum_{d|n, dA008683(n/d) * A063994(d).

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).
Showing 1-10 of 28 results. Next