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 1-5 of 5 results.

A366801 Arithmetic derivative without its inherited divisor applied to the Doudna sequence: a(n) = A342001(A005940(1+n)).

Original entry on oeis.org

0, 1, 1, 2, 1, 5, 2, 3, 1, 7, 8, 8, 2, 7, 3, 4, 1, 9, 10, 12, 12, 31, 13, 11, 2, 9, 11, 10, 3, 9, 4, 5, 1, 13, 14, 16, 16, 41, 17, 17, 18, 59, 71, 46, 19, 41, 18, 14, 2, 11, 13, 14, 17, 37, 16, 13, 3, 11, 14, 12, 4, 11, 5, 6, 1, 15, 16, 24, 18, 61, 25, 23, 20, 87, 103, 62, 27, 55, 24, 22, 24, 113, 131, 94, 167, 247
Offset: 0

Views

Author

Antti Karttunen, Oct 24 2023

Keywords

Crossrefs

Cf. A003415, A005940, A342001, A344026, A366802 (rgs-transform).
Cf. also A342002.

Programs

A366805 Lexicographically earliest infinite sequence such that a(i) = a(j) => A366803(i) = A366803(j) for all i, j >= 0.

Original entry on oeis.org

1, 2, 2, 2, 2, 3, 2, 4, 2, 5, 6, 3, 2, 4, 4, 4, 2, 7, 8, 5, 9, 10, 5, 5, 2, 4, 3, 4, 4, 11, 4, 3, 2, 12, 13, 7, 10, 14, 7, 15, 16, 17, 18, 10, 7, 15, 9, 5, 2, 4, 3, 4, 5, 5, 4, 3, 4, 6, 8, 11, 4, 3, 3, 3, 2, 19, 10, 12, 16, 20, 12, 19, 21, 22, 23, 14, 12, 19, 10, 15, 24, 25, 26, 17, 27, 26, 17, 24, 12, 19, 14, 15
Offset: 0

Views

Author

Antti Karttunen, Oct 26 2023

Keywords

Comments

Restricted growth sequence transform of A366803.
The scatter plot has quite interesting structure.

Crossrefs

Programs

  • PARI
    \\ Needs also program from A366803:
    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; };
    v366805 = rgs_transform(vector(1+up_to,n,A366803(n-1)));
    A366805(n) = v366805[1+n];

A366796 Lexicographically earliest infinite sequence such that a(i) = a(j) => A366795(i) = A366795(j) for all i, j >= 0.

Original entry on oeis.org

1, 2, 3, 1, 4, 5, 1, 2, 6, 7, 8, 3, 1, 2, 3, 1, 5, 8, 9, 4, 10, 11, 4, 5, 1, 2, 3, 1, 4, 5, 1, 2, 12, 13, 10, 6, 11, 14, 6, 7, 14, 15, 16, 8, 6, 7, 8, 3, 1, 2, 3, 1, 4, 5, 1, 2, 6, 7, 8, 6, 1, 2, 3, 1, 7, 17, 18, 5, 19, 15, 5, 8, 20, 21, 22, 9, 5, 8, 9, 4, 23, 22, 24, 10, 25, 25, 10, 11, 5, 8, 9, 4, 10, 11, 4, 5, 1
Offset: 0

Views

Author

Antti Karttunen, Oct 26 2023

Keywords

Comments

Restricted growth sequence transform of A366795.

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; };
    A001615(n) = if(1==n,n, my(f=factor(n)); prod(i=1, #f~, f[i, 1]^f[i, 2] + f[i, 1]^(f[i, 2]-1))); \\ After code in A001615
    A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); (t); };
    A344695(n) = gcd(sigma(n), A001615(n));
    A366795(n) = A344695(A005940(1+n));
    v366796 = rgs_transform(vector(1+up_to,n,A366795(n-1)));
    A366796(n) = v366796[1+n];

A369065 Lexicographically earliest infinite sequence such that a(i) = a(j) => A344026(i) = A344026(j) for all i, j >= 0.

Original entry on oeis.org

1, 2, 2, 3, 2, 4, 5, 6, 2, 7, 8, 9, 10, 11, 12, 13, 2, 14, 10, 15, 6, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 2, 27, 19, 13, 9, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 2, 55, 9, 56, 31, 57, 23, 34, 58, 59, 60, 61, 62, 63, 50, 64, 15, 65, 66
Offset: 0

Views

Author

Antti Karttunen, Jan 16 2024

Keywords

Comments

Restricted growth sequence transform of A344026, i.e., of the arithmetic derivative (A003415) as reordered by the Doudna sequence (A005940).

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]));
    A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); (t); };
    A344026(n) = A003415(A005940(1+n));
    v369065 = rgs_transform(vector(1+up_to,n,A344026(n-1)));
    A369065(n) = v369065[1+n];

A369457 Lexicographically earliest infinite sequence such that a(i) = a(j) => A369456(i) = A369456(j) for all i, j >= 0.

Original entry on oeis.org

1, 2, 2, 2, 2, 3, 4, 5, 2, 6, 7, 8, 4, 6, 2, 4, 2, 9, 10, 11, 12, 13, 14, 15, 4, 9, 15, 3, 5, 5, 8, 3, 2, 14, 16, 7, 17, 18, 19, 19, 20, 21, 22, 23, 24, 18, 11, 6, 4, 15, 14, 6, 19, 25, 17, 14, 5, 15, 16, 4, 8, 15, 3, 5, 2, 26, 17, 12, 20, 27, 28, 23, 29, 30, 31, 13, 32, 33, 7, 15, 34, 35, 36, 37, 38, 39, 40, 27, 41, 42, 43, 44, 45, 19
Offset: 0

Views

Author

Antti Karttunen, Jan 27 2024

Keywords

Comments

Restricted growth sequence transform of A369456.

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; };
    A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); (t); };
    A083345(n) = { my(f=factor(n)); numerator(vecsum(vector(#f~, i, f[i, 2]/f[i, 1]))); };
    A369456(n) = A083345(A005940(1+n));
    v369457 = rgs_transform(vector(1+up_to,n,A369456(n-1)));
    A369457(n) = v369457[1+n];
Showing 1-5 of 5 results.