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 1-2 of 2 results.

A369459 Lexicographically earliest infinite sequence such that a(i) = a(j) => A369458(i) = A369458(j) for all i, j >= 0.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Jan 28 2024

Keywords

Comments

Restricted growth sequence transform of A369458.
For all i, j >= 1:
A003602(i) = A003602(j) => A369467(i) = A369467(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; };
    A000265(n) = (n>>valuation(n,2));
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A163511(n) = if(!n,1,my(p=2, t=1); while(n>1, if(!(n%2), (t*=p), p=nextprime(1+p)); n >>= 1); (t*p));
    A369458(n) = A003415(A000265(A163511(n)));
    v369459 = rgs_transform(vector(1+up_to,n,A369458(n-1)));
    A369459(n) = v369459[1+n];

Formula

For all n > 0, a(n) = a(2*n) = a(A000265(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 1-2 of 2 results.