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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A331166 a(n) = min(n, A057889(n)), where A057889 is bijective base-2 reverse.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 11, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 19, 22, 27, 28, 23, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 37, 42, 43, 44, 45, 46, 47, 48, 35, 38, 51, 44, 43, 54, 55, 56, 39, 46, 55, 60, 47, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 69, 74, 83, 84, 85, 86, 87, 88, 77, 90, 91, 92, 93, 94, 95, 96, 67, 70
Offset: 0

Views

Author

Antti Karttunen, Jan 12 2020

Keywords

Comments

There is a large number of sequences b, related to binary expansion of n (A007088), for which it holds that b(n) = b(a(n)) for all n >= 0 (or n >= 1). For example, we have:
For all i, j:
a(i) = a(j) => A002487(i) = A002487(j),
a(i) = a(j) => A005811(i) = A005811(j),
a(i) = a(j) => A286622(i) = A286622(j) => A000120(i) = A000120(j).
For all i, j > 0:
a(i) = a(j) => A007814(i) = A007814(j),
a(i) = a(j) => A280505(i) = A280505(j),
a(i) = a(j) => A305788(i) = A305788(j) => A091222(i) = A091222(j).

Crossrefs

Programs

Formula

a(n) = min(n, A057889(n)).

A331303 Lexicographically earliest infinite sequence such that a(i) = a(j) => f(i) = f(j), where f(n) = min(n, A263273(n)), and A263273 is bijective base-3 reverse.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 11, 19, 15, 14, 20, 21, 17, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 27, 33, 34, 35, 36, 37, 38, 39, 40, 30, 41, 42, 38, 43, 44, 45, 46, 47, 25, 48, 29, 33, 49, 50, 41, 51, 40, 28, 49, 37, 36, 52, 53, 43, 54, 55, 31, 51, 44, 39, 54, 56, 46, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69
Offset: 0

Views

Author

Antti Karttunen, Jan 18 2020

Keywords

Comments

Restricted growth sequence transform of A331173. See comments in that sequence.

Crossrefs

Cf. also A331300.

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; };
    A030102(n) = { my(r=[n%3]); while(0A263273 = n -> if(!n,n,A030102(n/(3^valuation(n,3))) * (3^valuation(n, 3)));
    A331173(n) = min(n, A263273(n));
    v331303 = rgs_transform(vector(1+up_to,n,A331173(n-1)));
    A331303(n) = v331303[1+n];
Showing 1-2 of 2 results.