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 1-4 of 4 results.

A320115 Filter sequence for counting the residue classes mod 4 of divisors of n.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 3, 7, 8, 9, 3, 10, 5, 6, 11, 12, 5, 13, 3, 14, 11, 6, 3, 15, 16, 9, 11, 10, 5, 17, 3, 18, 11, 9, 11, 19, 5, 6, 11, 20, 5, 17, 3, 10, 21, 6, 3, 22, 8, 23, 11, 14, 5, 17, 11, 15, 11, 9, 3, 24, 5, 6, 25, 26, 27, 17, 3, 14, 11, 17, 3, 28, 5, 9, 25, 10, 11, 17, 3, 29, 30, 9, 3, 24, 27, 6, 11, 15, 5, 31, 11, 10, 11, 6, 11, 32, 5, 13, 25, 33, 5, 17, 3, 20
Offset: 1

Views

Author

Antti Karttunen, Oct 06 2018

Keywords

Comments

Restricted growth sequence transform of A320114.
For all i, j:
A319994(i) = A319994(j) => a(i) = a(j),
A320004(i) = A320004(j) => a(i) = a(j),
a(i) = a(j) => A002654(i) = A002654(j).

Crossrefs

Programs

  • PARI
    up_to = 100000;
    A320114(n) = { my(m=1); fordiv(n,d,if(d>1, m *= prime(1+(d%4)))); (m); };
    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; };
    v320115 = rgs_transform(vector(up_to,n,A320114(n)));
    A320115(n) = v320115[n];

A320117 Filter sequence for counting the residue classes mod 6 of divisors of n.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 5, 11, 7, 12, 13, 14, 5, 15, 7, 16, 17, 10, 5, 18, 19, 12, 20, 21, 5, 22, 7, 23, 13, 10, 24, 25, 7, 12, 17, 26, 5, 27, 7, 16, 28, 10, 5, 29, 30, 31, 13, 21, 5, 32, 24, 33, 17, 10, 5, 34, 7, 12, 35, 36, 24, 22, 7, 16, 13, 37, 5, 38, 7, 12, 39, 21, 24, 27, 7, 40, 41, 10, 5, 42, 24, 12, 13, 26, 5, 43, 44, 16, 17, 10, 24, 45, 7, 46, 28, 47, 5, 22, 7, 33
Offset: 1

Views

Author

Antti Karttunen, Oct 06 2018

Keywords

Comments

Restricted growth sequence transform of A320116.
For all i, j:
A319717(i) = A319717(j) => a(i) = a(j),
A319996(i) = A319996(j) => a(i) = a(j),
A320113(i) = A320113(j) => a(i) = a(j),
a(i) = a(j) => A002324(i) = A002324(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; };
    A320116(n) = { my(m=1); fordiv(n,d,if(d>1, m *= prime(1+(d%6)))); (m); };
    v320117 = rgs_transform(vector(up_to,n,A320116(n)));
    A320117(n) = v320117[n];

A320109 Filter sequence for counting the residue classes mod 8 of divisors of n.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 3, 11, 5, 12, 13, 14, 15, 16, 3, 17, 13, 6, 7, 18, 19, 10, 20, 21, 5, 22, 7, 23, 20, 24, 13, 25, 5, 6, 13, 26, 15, 22, 3, 11, 27, 12, 7, 28, 29, 30, 20, 17, 5, 31, 13, 32, 20, 10, 3, 33, 5, 12, 34, 35, 36, 31, 3, 37, 13, 22, 7, 38, 15, 10, 39, 11, 13, 22, 7, 40, 41, 24, 3, 33, 36, 6, 13, 18, 15, 42, 13, 21, 13, 12, 13, 43, 15, 44, 45, 46, 5, 31, 7, 26
Offset: 1

Views

Author

Antti Karttunen, Oct 06 2018

Keywords

Comments

Restricted growth sequence transform of A320108.
For all i, j: a(i) = a(j) => A320115(i) = A320115(j).

Crossrefs

Programs

  • PARI
    up_to = 100000;
    A320108(n) = { my(m=1); fordiv(n,d,if(d>1, m *= prime(1+(d%8)))); (m); };
    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; };
    v320109 = rgs_transform(vector(up_to,n,A320108(n)));
    A320109(n) = v320109[n];

A320112 a(n) = Product_{d|n, d>1} prime(1+(d mod 12)).

Original entry on oeis.org

1, 5, 7, 55, 13, 595, 19, 1265, 203, 2015, 37, 13090, 3, 475, 637, 13915, 13, 293335, 19, 509795, 3857, 5735, 37, 602140, 39, 75, 1421, 57475, 13, 28534415, 19, 320045, 7511, 2015, 9139, 12906740, 3, 475, 147, 128978135, 13, 27866825, 19, 1450955, 535717, 5735, 37, 13247080, 57, 30225, 637, 9075, 13, 34906865, 9139, 30404275, 3857, 2015, 37
Offset: 1

Views

Author

Antti Karttunen, Oct 06 2018

Keywords

Crossrefs

Cf. A320113 (rgs-transform).

Programs

  • PARI
    A320112(n) = { my(m=1); fordiv(n,d,if(d>1, m *= prime(1+(d%12)))); (m); };

Formula

a(n) = Product_{d|n, d>1} prime(1+(d mod 12)).
Showing 1-4 of 4 results.