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.

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A366286 Lexicographically earliest infinite sequence such that a(i) = a(j) => A366285(i) = A366285(j) for all i, j >= 0, where A366285(n) is the denominator of n / A366275(n).

Original entry on oeis.org

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

Views

Author

Antti Karttunen, Oct 07 2023

Keywords

Comments

Restricted growth sequence transform of A366285.

Crossrefs

Cf. also A365393, A365431 (compare the scatter plots).

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; };
    A366285(n) = { my(u=A366275(n)); (u/gcd(n,u)); }; \\ Uses also the program given in A366275.
    v366286 = rgs_transform(vector(1+up_to,n,A366285(n-1)));
    A366286(n) = v366286[1+n];

A366283 a(n) = gcd(n, A366275(n)), where A366275 is the Cat's tongue permutation.

Original entry on oeis.org

1, 1, 2, 3, 4, 1, 6, 1, 8, 9, 2, 1, 12, 1, 2, 1, 16, 1, 18, 1, 4, 3, 2, 1, 24, 25, 2, 1, 4, 1, 2, 1, 32, 3, 2, 5, 36, 1, 2, 3, 8, 1, 6, 1, 4, 3, 2, 1, 48, 1, 50, 1, 4, 1, 2, 55, 8, 1, 2, 1, 4, 1, 2, 1, 64, 1, 6, 1, 4, 3, 10, 1, 72, 1, 2, 15, 4, 7, 6, 1, 16, 3, 2, 1, 12, 5, 2, 3, 8, 1, 6, 7, 4, 3, 2, 1, 96, 1, 2, 1, 100
Offset: 0

Views

Author

Antti Karttunen, Oct 07 2023

Keywords

Crossrefs

Differs from related A364255 for the first time at n=25, where a(25) = 25, while A364255(25) = 5.

Programs

Formula

a(n) = gcd(n,A366282(n)) = gcd(A366275(n),A366282(n)).
a(n) = n / A366284(n) = A366275(n) / A366285(n).

A366375 a(n) = A332214(n) / gcd(n, A332214(n)), where A332214 is the Mersenne-prime fixing variant of permutation A163511.

Original entry on oeis.org

1, 2, 2, 1, 2, 9, 1, 1, 2, 3, 9, 49, 1, 21, 1, 1, 2, 81, 3, 343, 9, 7, 49, 25, 1, 63, 21, 35, 1, 15, 1, 1, 2, 81, 81, 343, 3, 1029, 343, 125, 9, 441, 7, 175, 49, 5, 25, 961, 1, 27, 63, 245, 21, 105, 35, 31, 1, 15, 15, 217, 1, 93, 1, 11, 2, 729, 81, 16807, 81, 2401, 343, 625, 3, 3087, 1029, 35, 343, 375, 125, 29791, 9, 49
Offset: 0

Views

Author

Antti Karttunen, Oct 08 2023

Keywords

Comments

Denominator of n / A332214(n).

Crossrefs

Cf. A332214, A366372, A366373, A366374 (numerators), A366376 (rgs-transform).
Cf. also A364492, A366285.

Programs

Formula

a(n) = A332214(n) / A366373(n) = A332214(n) / gcd(n, A332214(n)).

A366284 a(n) = n / gcd(n, A366275(n)), where A366275 is the Cat's tongue permutation.

Original entry on oeis.org

0, 1, 1, 1, 1, 5, 1, 7, 1, 1, 5, 11, 1, 13, 7, 15, 1, 17, 1, 19, 5, 7, 11, 23, 1, 1, 13, 27, 7, 29, 15, 31, 1, 11, 17, 7, 1, 37, 19, 13, 5, 41, 7, 43, 11, 15, 23, 47, 1, 49, 1, 51, 13, 53, 27, 1, 7, 57, 29, 59, 15, 61, 31, 63, 1, 65, 11, 67, 17, 23, 7, 71, 1, 73, 37, 5, 19, 11, 13, 79, 5, 27, 41, 83, 7, 17, 43, 29, 11
Offset: 0

Views

Author

Antti Karttunen, Oct 07 2023

Keywords

Comments

Numerator of n / A366275(n).

Crossrefs

Cf. also A364491.

Programs

Formula

a(n) = n / A366283(n) = n / gcd(n, A366275(n))
Showing 1-4 of 4 results.