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 1-9 of 9 results.

A366806 Lexicographically earliest infinite sequence such that a(i) = a(j) => A324186(i) = A324186(j) for all i, j >= 0, where A324186 is the sum of odd divisors permuted by A163511.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Oct 26 2023

Keywords

Comments

Restricted growth sequence transform of A324186.

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; };
    A000593(n) = sigma(n>>valuation(n, 2)); \\ From A000593
    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));
    A324186(n) = A000593(A163511(n));
    v366806 = rgs_transform(vector(1+up_to,n,A324186(n-1)));
    A366806(n) = v366806[1+n];

Formula

For all n >= 1, a(n) = a(2*n) = a(A000265(n)).

A324184 a(n) = sigma(A163511(n)).

Original entry on oeis.org

1, 3, 7, 4, 15, 13, 12, 6, 31, 40, 39, 31, 28, 24, 18, 8, 63, 121, 120, 156, 91, 124, 93, 57, 60, 78, 72, 48, 42, 32, 24, 12, 127, 364, 363, 781, 280, 624, 468, 400, 195, 403, 372, 342, 217, 228, 171, 133, 124, 240, 234, 248, 168, 192, 144, 96, 90, 104, 96, 72, 56, 48, 36, 14, 255, 1093, 1092, 3906, 847, 3124, 2343, 2801, 600
Offset: 0

Views

Author

Antti Karttunen, Feb 17 2019

Keywords

Crossrefs

Programs

  • PARI
    A324184(n) = if(!n,1,my(p=2,mp=p*p,m=1); while(n>1, if(n%2, p=nextprime(1+p); mp = p*p, if((2==n)||!(n%4),mp *= p,m *= (mp-1)/(p-1))); n >>= 1); (m*(mp-1)/(p-1)));
    
  • PARI
    A163511(n) = if(!n,1,my(p=2, t=1); while(n>1, if(!(n%2), (t*=p), p=nextprime(p+1)); n >>= 1); (t*p));
    A324184(n) = sigma(A163511(n));
    
  • Python
    from sympy import nextprime
    def A324184(n):
        if n:
            c, p = 1, 1
            while n:
                c *= ((p:=nextprime(p))**(s:=(~n&n-1).bit_length()+1)-1)//(p-1)
                n >>= s
            return c*(p**(s+1)-1)//(p**s-1)
        return 1 # Chai Wah Wu, Jul 25 2023

Formula

a(n) = A000203(A163511(n)).
For n >= 1, a(n) = A324054(A054429(n)).

A366881 Lexicographically earliest infinite sequence such that a(i) = a(j) => A206787(A163511(i)) = A206787(A163511(j)) and A336651(A163511(n)) = A336651(A163511(j)) for all i, j >= 0.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Nov 04 2023

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A206787(A163511(n)), A336651(A163511(n))].
Restricted growth sequence transform of sequence b(n) = A351461(A163511(n)).
For all i, j >= 0:
a(i) = a(j) => A324186(i) = A324186(j), (similarly for A366806)
a(i) = a(j) => A366885(i) = A366885(j). (similarly for A366886).

Crossrefs

Differs from A366806 for the first time at n=105, where a(105) = 52, while A366806(105) = 19.

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; };
    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));
    A206787(n) = sumdiv(n, d, d*issquarefree(2*d));
    A336651(n) = { my(f=factor(n>>valuation(n,2))); prod(i=1, #f~, f[i,1]^(f[i,2]-1)); };
    A366881aux(n) = [A206787(A163511(n)), A336651(A163511(n))];
    v366881 = rgs_transform(vector(1+up_to,n,A366881aux(n-1)));
    A366881(n) = v366881[1+n];

Formula

For all n >= 1, a(n) = a(2*n) = a(A000265(n)).

A366797 Number of odd divisors permuted by A163511: a(n) = A001227(A163511(n)).

Original entry on oeis.org

1, 1, 1, 2, 1, 3, 2, 2, 1, 4, 3, 3, 2, 4, 2, 2, 1, 5, 4, 4, 3, 6, 3, 3, 2, 6, 4, 4, 2, 4, 2, 2, 1, 6, 5, 5, 4, 8, 4, 4, 3, 9, 6, 6, 3, 6, 3, 3, 2, 8, 6, 6, 4, 8, 4, 4, 2, 6, 4, 4, 2, 4, 2, 2, 1, 7, 6, 6, 5, 10, 5, 5, 4, 12, 8, 8, 4, 8, 4, 4, 3, 12, 9, 9, 6, 12, 6, 6, 3, 9, 6, 6, 3, 6, 3, 3, 2, 10, 8, 8, 6, 12, 6, 6
Offset: 0

Views

Author

Antti Karttunen, Oct 27 2023

Keywords

Crossrefs

Cf. A001227, A163511, A366798 (rgs-transform).
Cf. also A324186, A366873.

Programs

  • PARI
    A001227(n) = numdiv(n>>valuation(n, 2));
    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));
    A366797(n) = A001227(A163511(n));

Formula

a(n) = 2*A366873(n) - A324186(n).

A366873 a(n) = A113415(A163511(n)), where A113415(n) is the average of number of and sum of odd divisors of n.

Original entry on oeis.org

1, 1, 1, 3, 1, 8, 3, 4, 1, 22, 8, 17, 3, 14, 4, 5, 1, 63, 22, 80, 8, 65, 17, 30, 3, 42, 14, 26, 4, 18, 5, 7, 1, 185, 63, 393, 22, 316, 80, 202, 8, 206, 65, 174, 17, 117, 30, 68, 3, 124, 42, 127, 14, 100, 26, 50, 4, 55, 18, 38, 5, 26, 7, 8, 1, 550, 185, 1956, 63, 1567, 393, 1403, 22, 1020, 316, 1204, 80, 804, 202
Offset: 0

Views

Author

Antti Karttunen, Oct 27 2023

Keywords

Crossrefs

Cf. A113415, A163511, A366874 (rgs-transform).
Cf. also A324186, A366797, A366875.

Programs

  • PARI
    A113415(n) = if(n<1, 0, sumdiv(n, d, if(d%2, (d+1)/2)));
    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));
    A366873(n) = A113415(A163511(n));

Formula

a(n) = (1/2) * (A324186(n)+A366797(n)).

A366885 Dedekind psi function applied to the odd part of n, permuted by A163511: a(n) = A347385(A163511(n)).

Original entry on oeis.org

1, 1, 1, 4, 1, 12, 4, 6, 1, 36, 12, 30, 4, 24, 6, 8, 1, 108, 36, 150, 12, 120, 30, 56, 4, 72, 24, 48, 6, 32, 8, 12, 1, 324, 108, 750, 36, 600, 150, 392, 12, 360, 120, 336, 30, 224, 56, 132, 4, 216, 72, 240, 24, 192, 48, 96, 6, 96, 32, 72, 8, 48, 12, 14, 1, 972, 324, 3750, 108, 3000, 750, 2744, 36, 1800, 600, 2352
Offset: 0

Views

Author

Antti Karttunen, Nov 04 2023

Keywords

Crossrefs

Cf. A001615, A163511, A347385, A366886 (rgs-transform).
Cf. also A324186.

Programs

  • PARI
    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));
    A347385(n) = if(1==n,n, my(f=factor(n>>valuation(n, 2))); prod(i=1, #f~, f[i, 1]^f[i, 2] + f[i, 1]^(f[i, 2]-1)));
    A366885(n) = A347385(A163511(n));

A366892 a(n) = A336652(A163511(n)).

Original entry on oeis.org

1, 1, 1, 3, 1, 12, 3, 5, 1, 39, 12, 30, 3, 15, 5, 7, 1, 120, 39, 155, 12, 90, 30, 56, 3, 60, 15, 35, 5, 21, 7, 11, 1, 363, 120, 780, 39, 465, 155, 399, 12, 360, 90, 280, 30, 168, 56, 132, 3, 195, 60, 210, 15, 105, 35, 77, 5, 84, 21, 55, 7, 33, 11, 13, 1, 1092, 363, 3905, 120, 2340, 780, 2800, 39, 1860, 465, 1995
Offset: 0

Views

Author

Antti Karttunen, Nov 04 2023

Keywords

Crossrefs

Cf. A163511, A336652, A366893 (rgs-transform).
Cf. also A324186.

Programs

  • PARI
    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));
    A336652(n) = if(1==n,n,my(f=factor(n)); prod(i=1,#f~,if(2==f[i,1],1,-1+(((f[i,1]^(1+f[i,2]))-1) / (f[i,1]-1)))));
    A366892(n) = A336652(A163511(n));

A366894 a(n) = A336699(A163511(n)).

Original entry on oeis.org

1, 1, 1, 1, 1, 7, 1, 1, 1, 3, 7, 1, 1, 1, 1, 1, 1, 61, 3, 5, 7, 1, 1, 29, 1, 5, 1, 1, 1, 1, 1, 1, 1, 23, 61, 391, 3, 5, 5, 13, 7, 101, 1, 43, 1, 29, 29, 67, 1, 1, 5, 1, 1, 1, 1, 1, 1, 7, 1, 5, 1, 1, 1, 1, 1, 547, 23, 977, 61, 391, 391, 1401, 3, 127, 5, 19, 5, 13, 13, 23, 7, 39, 101, 221, 1, 43, 43, 67, 1, 371, 29, 25, 29
Offset: 0

Views

Author

Antti Karttunen, Jan 03 2024

Keywords

Crossrefs

Cf. A000265, A000593, A163511, A324186, A336699, A351565, A366895 (rgs-transform).

Programs

Formula

a(n) = A351565(A324186(n)).

A366895 Lexicographically earliest infinite sequence such that a(i) = a(j) => A366894(i) = A366894(j) for all i, j >= 0.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Jan 03 2024

Keywords

Comments

Restricted growth sequence transform of A366894.
For all i, j >= 0:
A366881(i) = A366881(j) => A366806(i) = A366806(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));
    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));
    A336699(n) = A000265(1+A000265(sigma(A000265(n))));
    A366894(n) = A336699(A163511(n));
    v366895 = rgs_transform(vector(1+up_to,n,A366894(n-1)));
    A366895(n) = v366895[1+n];
Showing 1-9 of 9 results.