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 1-6 of 6 results.

A369051 Lexicographically earliest infinite sequence such that a(i) = a(j) => A003415(i) = A003415(j) and A085731(i) = A085731(j), for all i, j >= 1.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Jan 15 2024

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A003415(n), A085731(n)], or equally, of the pair [A003415(n), A083345(n)], or equally, of the pair [A083345(n), A085731(n)].
For all i, j: A369050(i) = A369050(j) => A344025(i) = A344025(j) => a(i) = a(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; };
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A085731(n) = gcd(A003415(n),n);
    Aux369051(n) = [A003415(n), A085731(n)];
    v369051 = rgs_transform(vector(up_to, n, Aux369051(n)));
    A369051(n) = v369051[n];

A344025 Lexicographically earliest infinite sequence such that a(i) = a(j) => A003415(i) = A003415(j) and A003557(i) = A003557(j), for all i, j >= 1.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, May 07 2021

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A003415(n), A003557(n)], where A003415(n) is the arithmetic derivative of n, and A003557(n) is n divided by its largest squarefree divisor.
For all i, j:
parent(i) = parent(j) => a(i) = a(j),
a(i) = a(j) => A342001(i) = A342001(j),
a(i) = a(j) => A369051(i) = A369051(j) => A085731(i) = A085731(j).
Where "parent" can be any of the sequences A351236, A351260, A353520, A353521, A369050, for example.

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; };
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A003557(n) = (n/factorback(factorint(n)[, 1]));
    Aux344025(n) = [A003415(n), A003557(n)];
    v344025 = rgs_transform(vector(up_to, n, Aux344025(n)));
    A344025(n) = v344025[n];

A369049 a(n) = n mod n', where n' is the arithmetic derivative of n, A003415.

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 8, 3, 3, 0, 12, 0, 5, 7, 16, 0, 18, 0, 20, 1, 9, 0, 24, 5, 11, 0, 28, 0, 30, 0, 32, 5, 15, 11, 36, 0, 17, 7, 40, 0, 1, 0, 44, 6, 21, 0, 48, 7, 5, 11, 52, 0, 54, 7, 56, 13, 27, 0, 60, 0, 29, 12, 64, 11, 5, 0, 68, 17, 11, 0, 72, 0, 35, 20, 76, 5, 7, 0, 80, 81, 39, 0, 84, 19, 41, 23, 88, 0, 90, 11
Offset: 2

Views

Author

Antti Karttunen, Jan 15 2024

Keywords

Crossrefs

Cf. A003415, A085731 [= gcd(A003415(n), a(n))].
Cf. also A328382, A342014, A369050.

Programs

  • Mathematica
    Array[Mod[#, #  Total[#2/#1 & @@@ FactorInteger[#]]] &, 120, 2] (* Michael De Vlieger, Jan 15 2024 *)
  • PARI
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A369049(n) = (n % A003415(n));

Formula

a(n) = n mod A003415(n).

A373150 Lexicographically earliest infinite sequence such that a(i) = a(j) => f(i) = f(j), where f(1) = 1, and for n>1, f(n) = [A003415(n), A085731(n), A373148(n)], for all i, j >= 1.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, May 27 2024

Keywords

Comments

Restricted growth sequence transform of the function f defined as: f(1) = 1, and for n>1, f(n) = [A003415(n), A085731(n), A373148(n)].
For all i, j >= 1:
A305800(i) = A305800(j) => a(i) = a(j),
a(i) = a(j) => A369051(i) = A369051(j),
a(i) = a(j) => A373151(i) = A373151(j) => A373143(i) = A373143(j).

Crossrefs

Differs from A369050 for the first time at n=91, where a(91)=67, while A369050(91)=37.
Differs from A300833 for the first time at n=133, where a(133)=133, while A300833(133)=50.

Programs

  • PARI
    up_to = 100000;
    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; };
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A085731(n) = gcd(A003415(n),n);
    A002110(n) = prod(i=1,n,prime(i));
    A276085(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*A002110(primepi(f[k, 1])-1)); };
    A373148(n) = (A276085(n)%A003415(n));
    Aux373150(n) = if(1==n,1,[A003415(n), A085731(n), A373148(n)]);
    v373150 = rgs_transform(vector(up_to, n, Aux373150(n)));
    A373150(n) = v373150[n];

A369046 Lexicographically earliest infinite sequence such that a(i) = a(j) => A003415(i) = A003415(j) and A069359(i) = A069359(j), for all i, j >= 1.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Jan 18 2024

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A003415(n), A069359(n)].
For all i,j >= 1:
A369050(i) = A369050(j) => a(i) = a(j), [Conjectured]
a(i) = a(j) => A329039(i) = A329039(j) => A008966(i) = A008966(j).

Crossrefs

Cf. also A369050, A369051.
Differs from A351236 for the first time at n=91, where a(91) = 37, while A351236(91) = 64.
Differs from A344025 for the first time at n=140, where a(140) = 97, while A344025(140) = 92.

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; };
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A069359(n) = (n*sumdiv(n, d, isprime(d)/d));
    Aux369046(n) = [A003415(n), A069359(n)];
    v369046 = rgs_transform(vector(up_to, n, Aux369046(n)));
    A369046(n) = v369046[n];

A369040 Lexicographically earliest infinite sequence such that a(i) = a(j) => A003415(i) = A003415(j) and A342014(i) = A342014(j), for all i, j >= 1.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Jan 18 2024

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A003415(n), A342014(n)].
For all i, j >= 1:
A369050(i) = A369050(j) => a(i) = a(j), [Conjectured]
a(i) = a(j) => A341625(i) = A341625(j).

Crossrefs

Programs

  • PARI
    up_to = 100000;
    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; };
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A342014(n) = (A003415(n)%n);
    Aux369040(n) = [A003415(n), A342014(n)];
    v369040 = rgs_transform(vector(up_to, n, Aux369040(n)));
    A369040(n) = v369040[n];
Showing 1-6 of 6 results.