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 1-6 of 6 results.

A169863 Complement of A093848.

Original entry on oeis.org

3, 6, 8, 10, 13, 15, 17, 19, 22, 24, 26, 28, 30, 32, 35, 37, 39, 41, 43, 45, 47, 49, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 73, 75, 77, 79, 81, 83, 85, 87, 89, 91, 93, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 123
Offset: 1

Views

Author

N. J. A. Sloane, Jun 27 2010, following a suggestion from Jeremy Gardiner

Keywords

Crossrefs

Cf. A093848.

A169864 The sequence S of a pair S, T generalizing Golomb's sequence A001462 and the pair A093848, A169863. See Comments for definition.

Original entry on oeis.org

1, 3, 4, 6, 8, 10, 12, 13, 15, 17, 19, 21, 23, 25, 26, 28, 30, 32, 34, 36, 38, 40, 42, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 91, 93
Offset: 1

Views

Author

N. J. A. Sloane, Jun 27 2010, following a posting from Eric Angelini to the Sequence Fans Mailing List, Jun 22, 2010

Keywords

Comments

S is built with the rules [1] that you cannot insert any integer between two "touching" runs (run 1,3 is followed by 4,6,8,10,12; there is no integer between 3 and 4) and [2] that S and T share no integer.
T encodes the instructions for S.
It is not quite clear to me if T is the complement of S, or is merely disjoint from it.

Crossrefs

A169865 The sequence T of a pair S, T generalizing Golomb's sequence A001462 and the pair A093848, A169863. See Comments for definition.

Original entry on oeis.org

2, 5, 7, 9, 11, 14, 16, 18, 20, 22, 24, 27, 29, 31, 33, 35, 37, 39, 41, 44, 46
Offset: 1

Views

Author

N. J. A. Sloane, Jun 27 2010, following a posting from Eric Angelini to the Sequence Fans Mailing List, Jun 22, 2010

Keywords

Comments

S is built with the rules [1] that you cannot insert any integer between two "touching" runs (run 1,3 is followed by 4,6,8,10,12; there is no integer between 3 and 4) and [2] that S and T share no integer.

Crossrefs

A169866 The sequence S of a pair of complementary sequences (S, T) which are similar to the pairs (A093848, A169863), (A169864, A169865), except that here the lengths of the equal-parity runs of one sequence are given by the other.

Original entry on oeis.org

1, 3, 4, 6, 8, 10, 12, 11, 13, 15, 17, 19, 21, 23, 22, 24, 26, 28, 30, 32, 34, 36, 38, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86
Offset: 1

Views

Author

N. J. A. Sloane, Jun 27 2010, following a posting from Eric Angelini to the Sequence Fans Mailing List, Jun 22, 2010

Keywords

Crossrefs

A169867 The sequence T of a pair of complementary sequences (S, T) which are similar to the pairs (A093848, A169863), (A169864, A169865), except that here the lengths of the equal-parity runs of one sequence are given by the other.

Original entry on oeis.org

2, 5, 7, 9, 14, 16, 18, 20, 25, 27, 29, 31, 33, 35, 40, 42, 44, 46, 48, 50, 52, 54, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110
Offset: 1

Views

Author

N. J. A. Sloane, Jun 27 2010, following a posting from Eric Angelini to the Sequence Fans Mailing List, Jun 22, 2010

Keywords

Crossrefs

A114055 Lexicographically earliest strictly increasing sequence such that the run lengths of digits with equal parity in the sequence's digit stream yield the sequence itself.

Original entry on oeis.org

1, 2, 4, 5, 7, 9, 10, 20, 22, 31, 33, 35, 36, 40, 42, 44, 46, 51, 53, 55, 57, 59, 60, 62, 64, 66, 68, 80, 82, 84, 86, 88, 91, 93, 95, 97, 99, 111, 113, 115, 117, 200, 202, 204, 206, 208, 220, 222, 224, 226, 228, 231, 311, 313, 315, 317, 319, 331, 333, 335, 337
Offset: 1

Views

Author

Eric Angelini, Feb 02 2006

Keywords

Comments

A variant of A093848.

Examples

			(1),(2,4),(5,7,9,1)(0,20,22),(31,33,35,3)(6,40,42,44,46),(51,53,55,57,59),(60,62,64,66,68,80,82,84,86,88)... Those runs of equal parity digits are of length 1,2,4,5,7,9,10,20... which is the sequence itself.
		

Crossrefs

Programs

  • Python
    from itertools import groupby
    from itertools import count
    a = [1,2]
    while len(a)<100:a.append(next(k for k in count(a[-1]+1)if (b := [len(list(g))for _,g in(groupby(list(map(lambda d:int(d)%2,"".join(map(str,a))+str(k)))))])and all(b[i]==a[i]for i in range(len(b)-1))and not b[-1]>a[len(b)-1]))
    print(a) # Dominic McCarty, Mar 18 2025

Extensions

Name edited, a(40) and on corrected by Dominic McCarty, Mar 18 2025
Showing 1-6 of 6 results.