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 1-10 of 10 results.

A022305 Exactly half the first a(n) terms of A022303 are 1's.

Original entry on oeis.org

2, 4, 6, 10, 12, 14, 16, 18, 20, 22, 24, 26, 32, 34, 36, 38, 40, 42, 44, 46, 50, 52, 54, 56, 58, 60, 64, 66, 68, 70, 72, 74, 76, 78, 82, 84, 94, 100, 102, 112, 114, 118, 120, 122, 124, 126, 128, 132, 134, 136, 138, 140, 142, 144, 146, 148, 154, 156, 158
Offset: 0

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A022304 Index of n-th 1 in A022303.

Original entry on oeis.org

1, 3, 6, 9, 10, 12, 13, 16, 18, 19, 21, 24, 25, 27, 28, 30, 33, 36, 37, 39, 42, 44, 45, 47, 48, 51, 54, 55, 57, 60, 63, 64, 66, 67, 69, 72, 74, 75, 78, 81, 82, 84, 87, 90, 91, 93, 94, 97, 99, 100, 102, 105, 108, 109, 111, 112, 114, 117, 118, 120, 121, 124
Offset: 0

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A025516 Index of n-th 2 in A022303.

Original entry on oeis.org

2, 4, 5, 7, 8, 11, 14, 15, 17, 20, 22, 23, 26, 29, 31, 32, 34, 35, 38, 40, 41, 43, 46, 49, 50, 52, 53, 56, 58, 59, 61, 62, 65, 68, 70, 71, 73, 76, 77, 79, 80, 83, 85, 86, 88, 89, 92, 95, 96, 98, 101, 103, 104, 106, 107, 110, 113, 115, 116, 119, 122, 123, 125, 128, 131, 132, 134
Offset: 1

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A025517 Least k such that first k terms of A022303 contain n more 1's than 2's.

Original entry on oeis.org

1, 28, 253, 794, 821, 854, 1123, 1394, 1493, 1520, 1529, 193136, 193169, 194032, 194041, 195374, 196367, 196376, 198567, 198630, 199145, 199550, 199857, 200282, 201755, 201782, 201791, 205326, 205683, 205710, 205803, 206028, 206061, 206088
Offset: 1

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A025518 Least k such that first k terms of A022303 contain n more 2's than 1's.

Original entry on oeis.org

5, 8, 89, 374, 467, 6348, 6965, 7172, 7265, 7562, 7967, 20334, 20367, 21978, 22005, 25634, 25661, 25688, 27965, 39180, 39207, 42394, 43125, 43146, 48633, 48726, 48753, 49010, 49037, 49064, 49091, 49860, 50077, 50086, 50383, 50410, 50955, 51340, 52239
Offset: 1

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A025519 Least k>1 such that first n terms of A022303 repeat beginning at k-th term.

Original entry on oeis.org

3, 3, 10, 19, 19, 19, 28, 28, 28, 28, 28, 28, 55, 55, 82, 82, 82, 82, 82, 82, 82, 82, 82, 82, 460, 460, 460, 460, 460, 460, 460, 460, 460, 460, 460, 460, 460, 460, 460, 1096, 1096, 1096, 1096, 1096, 1096, 1096, 1096, 1096, 1096, 1096, 1096, 1096, 1096, 1096, 8079
Offset: 1

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A025520 Least k>1 such that reverse of first n terms of A022303 repeats beginning at k-th term.

Original entry on oeis.org

3, 2, 10, 15, 14, 13, 38, 146, 145, 144, 143, 142, 222, 221, 220, 219, 218, 217, 216, 215, 214, 374, 373, 372, 574, 573, 572, 571, 570, 569, 568, 567, 566, 565, 564, 563, 562, 561, 560, 7694, 7693, 7692, 7691, 7690, 7689, 7688, 7687, 7686, 7685, 7684, 7683, 7682
Offset: 1

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A025521 Least k>1 such that complement of first n terms of A022303 repeats beginning at k-th term.

Original entry on oeis.org

2, 2, 2, 15, 15, 15, 15, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691
Offset: 1

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A025522 Least k>1 such that reverse complement of first n terms of A022303 repeats beginning at k-th term.

Original entry on oeis.org

2, 3, 2, 19, 18, 17, 16, 24, 23, 22, 21, 20, 58, 57, 341, 340, 339, 338, 337, 336, 335, 334, 333, 332, 331, 330, 329, 328, 327, 326, 325, 324, 323, 322, 649, 648, 647, 646, 645, 863, 862, 861, 860, 859, 858, 857, 856, 855, 854, 853, 852, 851, 850, 849, 848, 847, 846, 845
Offset: 1

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A022300 The sequence a of 1's and 2's starting with (1,1,2,1) such that a(n) is the length of the (n+2)nd run of a.

Original entry on oeis.org

1, 1, 2, 1, 2, 1, 1, 2, 1, 1, 2, 1, 2, 2, 1, 2, 1, 1, 2, 1, 1, 2, 2, 1, 2, 2, 1, 2, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 1, 2, 2, 1, 2, 2, 1, 2, 1, 1, 2, 1, 1, 2, 2, 1, 2, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 1, 2, 2, 1, 2, 2, 1, 2, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 1, 2, 1, 2, 2, 1, 2, 2, 1, 1, 2, 1, 2, 2, 1, 2, 1, 1, 2, 2, 1, 2, 2, 1, 1
Offset: 1

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Comments

It appears that various properties and unsolved problems associated with the Kolakoski sequence, A000002, apply also to A022300.

Examples

			a(1) =1, so the 3rd run has length 1, so a(5) must be 2.
a(2) = 1, so the 4th run has length 1, so a(6) = 1.
a(3) = 2, so the 5th run has length 2, so a(7) = 1 and a(8) = 2.
a(4) = 1, so the 6th run has length 1, so a(9) = 1.
Globally, the runlength sequence of a is 2,1,1,1,2,1,2,1,1,2,1,1,2,...., and deleting the first two terms leaves a = A022300.
		

Crossrefs

Programs

  • Mathematica
    a = {1, 1, 2}; Do[a = Join[a, ConstantArray[If[Last[a] == 1, 2, 1], {a[[n]]}]], {n, 200}]; a
    (* Peter J. C. Moses, Apr 01 2016 *)

Extensions

Clarified and augmented by Clark Kimberling, Apr 02 2016
Showing 1-10 of 10 results.