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.

Previous Showing 11-20 of 20 results.

A323372 Lexicographically earliest sequence such that for all i, j, a(i) = a(j) => A003557(i) = A003557(j) and A323363(i) = A323363(j).

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 32, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 44, 49, 50, 51, 44, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 58, 62, 29, 65, 66, 67, 68, 69, 58, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 79
Offset: 1

Views

Author

Antti Karttunen, Jan 13 2019

Keywords

Comments

Restricted growth sequence transform of ordered pair [A003557(n), A323363(n)].
For all i, j:
a(i) = a(j) => A291751(i) = A291751(j),
a(i) = a(j) => A323364(i) = A323364(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; };
    DirInverse(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = -sumdiv(n, d, if(dA001615(n) = (n * sumdivmult(n, d, issquarefree(d)/d)); \\ From A001615
    v323363 = DirInverse(vector(up_to,n,A001615(n)));
    A323363(n) = v323363[n];
    A003557(n) = { my(f=factor(n)); for(i=1, #f~, f[i, 2] = f[i, 2]-1); factorback(f); };
    v323372 = rgs_transform(vector(up_to, n, [A003557(n), A323363(n)]));
    A323372(n) = v323372[n];

A319698 Filter sequence combining A003557(n) [n divided by largest squarefree divisor of n] with A319697(n) [sum of even squarefree divisors of n].

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Oct 31 2018

Keywords

Comments

Restricted growth sequence transform of ordered pair [A003557(n), A319697(n)].

Crossrefs

Cf also A291750, A291751.

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; };
    A003557(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 2] = f[i, 2]-1); factorback(f); }; \\ From A003557
    A319697(n) = sumdiv(n, d, (!(d%2))*issquarefree(d)*d);
    v319698 = rgs_transform(vector(up_to,n,[A003557(n),A319697(n)]));
    A319698(n) = v319698[n];

A322021 Lexicographically earliest such sequence a that a(i) = a(j) => A046523(i) = A046523(j) and A048250(i) = A048250(j), for all i, j.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 14, 15, 16, 12, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 26, 42, 43, 44, 45, 18, 42, 46, 47, 22, 42, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 54, 58, 61, 62, 63, 64, 26, 65, 54, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 52, 78, 79, 80, 81, 75, 82, 83, 26
Offset: 1

Views

Author

Antti Karttunen, Nov 29 2018

Keywords

Comments

Restricted growth sequence transform of A291758, which means that this is the lexicographically least sequence a, such that for all i, j: a(i) = a(j) <=> A291758(i) = A291758(j) <=> A046523(i) = A046523(j) and A048250(i) = A048250(j). That this is equal to the definition given in the title follows because any such lexicographically least sequence satisfying relation <=> is also the least sequence satisfying relation => with the same parameters.
For all i, j:
A295300(i) = A295300(j) => a(i) = a(j),
a(i) = a(j) => A304411(i) = A304411(j),
a(i) = a(j) => A304412(i) = A304412(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; };
    A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };  \\ From A046523
    A048250(n) = if(n<1, 0, sumdiv(n, d, if(core(d)==d, d)));
    v322021 = rgs_transform(vector(up_to, n, [A046523(n), A048250(n)]));
    A322021(n) = v322021[n];

A323238 Lexicographically earliest sequence such that for all i, j, a(i) = a(j) => f(i) = f(j), where f(n) = A291750(n) for all n, except for odd numbers n > 1, f(n) = 0.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Jan 08 2019

Keywords

Comments

For all i, j:
A319701(i) = A319701(j) => a(i) = a(j),
a(i) = a(j) => A146076(i) = A146076(j),
a(i) = a(j) => A319697(i) = A319697(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; };
    A003557(n) = { my(f=factor(n)); for(i=1, #f~, f[i, 2] = f[i, 2]-1); factorback(f); };
    A048250(n) = factorback(apply(p -> p+1,factor(n)[,1]));
    Aux323238(n) = if((n>1)&&(n%2),0,(1/2)*(2 + ((A003557(n)+A048250(n))^2) - A003557(n) - 3*A048250(n)));
    v323238 = rgs_transform(vector(up_to, n, Aux323238(n)));
    A323238(n) = v323238[n];

A369260 Lexicographically earliest infinite sequence such that a(i) = a(j) => A342671(i) = A342671(j) and A349162(i) = A349162(j), for all i, j >= 1.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 15, 23, 16, 24, 25, 26, 27, 28, 21, 29, 30, 31, 30, 32, 33, 34, 26, 35, 36, 37, 38, 39, 40, 28, 30, 41, 42, 43, 44, 45, 46, 47, 44, 48, 49, 50, 51, 52, 53, 37, 54, 55, 56, 57, 58, 59, 60, 57, 44, 61, 62, 63, 41, 64, 60, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 65, 79, 57
Offset: 1

Views

Author

Antti Karttunen, Jan 25 2024

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A342671(n), A349162(n)], or equally, of the pair [A000203(n), A342671(n)], or equally, of the pair [A000203(n), A349162(n)].
For all i, j >= 1:
A369259(i) = A369259(j) => a(i) = a(j) => A286603(i) = A286603(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; };
    A003961(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
    A342671(n) = gcd(sigma(n), A003961(n));
    Aux369260(n) = { my(u=A342671(n)); [u, sigma(n)/u]; };
    v369260 = rgs_transform(vector(up_to, n, Aux369260(n)));
    A369260(n) = v369260[n];

A325381 Lexicographically earliest sequence such that a(i) = a(j) => A048250(i) = A048250(j) and A126795(i) = A126795(j) for all i, j.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, May 08 2019

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A048250(n), A126795(n)].

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; };
    A048250(n) = factorback(apply(p -> p+1,factor(n)[,1]));
    A126795(n) = gcd(n,A048250(n));
    v325381 = rgs_transform(vector(up_to,n,[A048250(n),A126795(n)]));
    A325381(n) = v325381[n];

A351441 Lexicographically earliest infinite sequence such that a(i) = a(j) => A003557(i) = A003557(j) and A351450(i) = A351450(j) for all i, j >= 1.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Feb 12 2022

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A003557(n), A351450(n)].
For all i, j >= 1:
a(i) = a(j) => A326042(i) = A326042(j),
a(i) = a(j) => A351455(i) = A351455(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; };
    A003557(n) = (n/factorback(factorint(n)[, 1]));
    A003961(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
    A048250(n) = factorback(apply(p -> p+1,factor(n)[,1]));
    A064989(n) = { my(f = factor(n>>valuation(n,2))); for(i=1, #f~, f[i,1] = precprime(f[i,1]-1)); factorback(f); };
    A351450(n) = A064989(A048250(A003961(n)));
    Aux351441(n) = [A003557(n), A351450(n)];
    v351441 = rgs_transform(vector(up_to, n, Aux351441(n)));
    A351441(n) = v351441[n];

A369261 Lexicographically earliest infinite sequence such that a(i) = a(j) => A324644(i) = A324644(j) and A369445(i) = A369445(j), for all i, j >= 1.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 15, 23, 16, 20, 24, 25, 26, 27, 21, 28, 29, 30, 29, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 29, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 35, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 62, 53, 51, 70, 71, 72, 58, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 63
Offset: 1

Views

Author

Antti Karttunen, Jan 25 2024

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A324644(n), A369445(n)], or equally, of the pair [A000203(n), A324644(n)], or equally, of the pair [A000203(n), A369445(n)].
For all i, j >= 1: a(i) = a(j) => A286603(i) = A286603(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; };
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A324644(n) = gcd(sigma(n),A276086(n));
    Aux369261(n) = { my(u=A324644(n)); [u, sigma(n)/u]; };
    v369261 = rgs_transform(vector(up_to, n, Aux369261(n)));
    A369261(n) = v369261[n];

A369259 Lexicographically earliest infinite sequence such that a(i) = a(j) => A003557(i) = A003557(j), A048250(i) = A048250(j) and A342671(i) = A342671(j), for all i, j >= 1.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 15, 23, 24, 25, 26, 27, 28, 29, 21, 30, 31, 32, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 29, 31, 43, 44, 45, 46, 47, 48, 49, 46, 50, 51, 52, 53, 54, 55, 39, 56, 57, 58, 59, 60, 61, 62, 59, 46, 63, 64, 65, 66, 67, 62, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 59
Offset: 1

Views

Author

Antti Karttunen, Jan 25 2024

Keywords

Comments

Restricted growth sequence transform of the triplet [A003557(j), A048250(i), A342671(n)].
For all i, j >= 1:
a(i) = a(j) => A323368(i) = A323368(j) => A291751(i) = A291751(j),
a(i) = a(j) => A369260(i) = A369260(j) => A286603(i) = A286603(j).

Crossrefs

Differs from related A296089 and A323368 for the first time at n=79, where a(79) = 69, while A296089(79) = A323368(79) = 51.

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; };
    A003557(n) = (n/factorback(factor(n)[, 1]));
    A003961(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
    A048250(n) = if(n<1, 0, sumdiv(n, d, if(core(d)==d, d)));
    A342671(n) = gcd(sigma(n), A003961(n));
    Aux369259(n) = [A003557(n), A048250(n), A342671(n)];
    v369259 = rgs_transform(vector(up_to, n, Aux369259(n)));
    A369259(n) = v369259[n];

A374485 Lexicographically earliest infinite sequence such that a(i) = a(j) => A350388(i) = A350388(j) and A351569(i) = A351569(j), for all i, j >= 1.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Aug 06 2024

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A350388(n), A351569(n)].
For all i, j >= 1: a(i) = a(j) => A000203(i) = A000203(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; };
    A350388(n) = { my(m=1, f=factor(n)); for(k=1,#f~,if(0==(f[k,2]%2), m *= (f[k,1]^f[k,2]))); (m); };
    A350389(n) = { my(m=1, f=factor(n)); for(k=1,#f~,if(1==(f[k,2]%2), m *= (f[k,1]^f[k,2]))); (m); };
    A351569(n) = sigma(A350389(n));
    Aux374485(n) = [A350388(n), A351569(n)];
    v374485 = rgs_transform(vector(up_to, n, Aux374485(n)));
    A374485(n) = v374485[n];
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