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 1-5 of 5 results.

A075170 Sequence A075171 interpreted as binary numbers and converted to decimal.

Original entry on oeis.org

0, 2, 10, 12, 44, 42, 50, 52, 180, 178, 170, 172, 204, 202, 210, 56, 184, 722, 714, 716, 684, 682, 690, 692, 820, 818, 810, 812, 844, 842, 226, 216, 728, 738, 2890, 2892, 2860, 2858, 2866, 2868, 2740, 2738, 2730, 2732, 2764, 2762, 2770, 696, 824, 3282
Offset: 0

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Author

Antti Karttunen, Sep 13 2002

Keywords

Crossrefs

Permutation of A014486. Same sequence shown in binary: A075171. The binary width of each term / 2 is given by A075172.

A075172 Number of edges in each rooted plane tree produced with the binary run length unranking algorithm presented in A075171.

Original entry on oeis.org

0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 3, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 4, 4, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 5, 5, 5, 4, 5, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7
Offset: 0

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Author

Antti Karttunen, Sep 13 2002

Keywords

Comments

Also the digital length of A075171(n)/ 2. Each value v occurs A000108(v) times.

Crossrefs

Permutation of A072643.

A075166 Natural numbers mapped to Dyck path encodings of the rooted plane trees obtained by recursing on the exponents of the prime factorization of n.

Original entry on oeis.org

0, 10, 1010, 1100, 101010, 101100, 10101010, 110100, 110010, 10101100, 1010101010, 10110100, 101010101010, 1010101100, 10110010, 111000, 10101010101010, 11001100, 1010101010101010, 1010110100, 1010110010
Offset: 1

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Author

Antti Karttunen, Sep 13 2002

Keywords

Comments

Note that we recurse on the exponent + 1 for all other primes except the largest one in the factorization. Thus for 6 = 3^1 * 2^1 we construct a tree by joining trees 1 and 2 with a new root node, for 7 = 7^1 * 5^0 * 3^0 * 2^0 we join four 1-trees (single leaves) with a new root node, for 8 = 2^3 we add a single edge below tree 3 and for 9 = 3^2 * 2^0 we join trees 2 and 1, to get the mirror image of tree 6. Compare to Matula/Goebel numbering of (unoriented) rooted trees as explained in A061773.

Examples

			The rooted plane trees encoded here are:
.....................o...............o.........o...o..o.......
.....................|...............|..........\./...|.......
.......o....o...o....o....o.o.o..o...o.o.o.o.o...o....o...o...
.......|.....\./.....|.....\|/....\./...\|.|/....|.....\./....
*......*......*......*......*......*......*......*......*.....
1......2......3......4......5......6......7......8......9.....
		

Crossrefs

Permutation of A063171. Same sequence shown in decimal: A075165. The digital length of each term / 2 (the number of o-nodes in the corresponding trees) is given by A075167. Cf. A075171, A007088.

Formula

a(n) = A007088(A075165(n)) = A106456(A106442(n)). - Antti Karttunen, May 09 2005

A075168 Position of A075170(n) in A014486.

Original entry on oeis.org

0, 1, 2, 3, 5, 4, 6, 7, 12, 11, 9, 10, 15, 14, 16, 8, 13, 30, 28, 29, 24, 23, 25, 26, 40, 39, 37, 38, 43, 42, 19, 18, 32, 33, 84, 85, 80, 79, 81, 82, 68, 67, 65, 66, 71, 70, 72, 27, 41, 114, 112, 113, 108, 107, 109, 110, 124, 123, 121, 122, 52, 51, 47, 17, 31, 89, 93, 94
Offset: 0

Views

Author

Antti Karttunen, Sep 13 2002

Keywords

Comments

See A075171.

Crossrefs

Inverse of A075169.

A075169 Position of A014486(n) in A075170.

Original entry on oeis.org

0, 1, 2, 3, 5, 4, 6, 7, 15, 10, 11, 9, 8, 16, 13, 12, 14, 63, 31, 30, 127, 255, 65535, 21, 20, 22, 23, 47, 18, 19, 17, 64, 32, 33, 128, 256, 65536, 26, 27, 25, 24, 48, 29, 28, 126, 2047, 4095, 62, 1023, 511, 131071, 61, 60, 254, 16383, 8191, 510, 32767
Offset: 0

Views

Author

Antti Karttunen, Sep 13 2002

Keywords

Comments

See A075171.

Crossrefs

Inverse of A075168.
Showing 1-5 of 5 results.