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.

A318890 Filter sequence combining the prime signature of n (A046523) with the prime signature of its conjugated prime factorization (A278221).

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 10, 15, 16, 12, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 14, 33, 34, 35, 36, 37, 38, 39, 40, 41, 18, 42, 43, 44, 45, 18, 46, 47, 48, 22, 31, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 39, 63, 64, 65, 66, 18, 67, 20, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 53, 36, 80, 81, 82, 83, 84, 85, 26, 86, 87, 88, 89, 90, 91, 39
Offset: 1

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Author

Antti Karttunen, Sep 16 2018

Keywords

Comments

Restricted growth sequence transform of A286454.
For all i, j: a(i) = a(j) => A318891(i) = A318891(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; };
    A064989(n) = {my(f); f = factor(n); if((n>1 && f[1,1]==2), f[1,2] = 0); for (i=1, #f~, f[i,1] = precprime(f[i,1]-1)); factorback(f)};
    A122111(n) = if(1==n,n,prime(bigomega(n))*A122111(A064989(n)));
    A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };  \\ From A046523
    A278221(n) = A046523(A122111(n));
    A318890aux(n) = [A046523(n), A278221(n)];
    v318890 = rgs_transform(vector(up_to,n,A318890aux(n)));
    A318890(n) = v318890[n];

A328469 Lexicographically earliest infinite sequence such that a(i) = a(j) => A020639(i) = A020639(j) and A046523(i) = A046523(j) for all i, j.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Oct 19 2019

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A020639(n), A046523(n)], where A020639(n) gives the smallest prime factor of n, while A046523(n) gives the prime signature of n.
For all i, j: a(i) = a(j) => A291761(i) = A291761(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; };
    A020639(n) = if(n>1, if(n>n=factor(n, 0)[1, 1], n, factor(n)[1, 1]), 1);
    A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); }; \\ From A046523
    Aux328469(n) = [A020639(n), A046523(n)];
    v328469 = rgs_transform(vector(up_to, n, Aux328469(n)));
    A328469(n) = v328469[n];

A331298 Lexicographically earliest infinite sequence such that a(i) = a(j) => A001222(i) = A001222(j) and A061395(i) = A061395(j) for all i, j.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Jan 18 2020

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A001222(n), A061395(n)].
For all i, j:
A318891(i) = A318891(j) => a(i) = a(j),
a(i) = a(j) => A331297(i) = A331297(j) => A326846(i) = A326846(j),
a(i) = a(j) => A331281(i) = A331281(j),
a(i) = a(j) => A331282(i) = A331282(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; };
    A061395(n) = if(1==n, 0, primepi(vecmax(factor(n)[, 1])));
    Aux331298(n) = [bigomega(n),A061395(n)];
    v331298 = rgs_transform(vector(up_to, n, Aux331298(n)));
    A331298(n) = v331298[n];

A336147 Lexicographically earliest infinite sequence such that a(i) = a(j) => A020639(i) = A020639(j) and A278221(i) = A278221(j), for all i, j >= 1.

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Jul 12 2020

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A020639(n), A278221(n)].
For all i, j:
A324400(i) = A324400(j) => A336146(i) = A336146(j) => a(i) = a(j),
a(i) = a(j) => A243055(i) = A243055(j),
a(i) = a(j) => A336150(i) = A336150(j).

Crossrefs

First differs from A322590 at a(70) = 28 instead of 44.

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; };
    A020639(n) = if(1==n, n, factor(n)[1, 1]);
    A064989(n) = {my(f); f = factor(n); if((n>1 && f[1,1]==2), f[1,2] = 0); for (i=1, #f~, f[i,1] = precprime(f[i,1]-1)); factorback(f)};
    A122111(n) = if(1==n,n,prime(bigomega(n))*A122111(A064989(n)));
    A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); }; \\ From A046523
    A278221(n) = A046523(A122111(n));
    Aux336147(n) = [A020639(n),A278221(n)];
    v336147 = rgs_transform(vector(up_to, n, Aux336147(n)));
    A336147(n) = v336147[n];
Showing 1-4 of 4 results.