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 18 results. Next

A306215 a(n) gives the length of A306211 after n generations.

Original entry on oeis.org

1, 2, 3, 5, 8, 13, 22, 37, 61, 100, 162, 260, 416, 663, 1053, 1664, 2617, 4102, 6416, 10029, 15684, 24561, 38531, 60560, 95334, 150238, 236878, 373449, 588441, 926449, 1457335, 2290726, 3599062, 5654352, 8886976, 13979961, 22020411, 34743031, 54922083
Offset: 1

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Author

Peter Kagey, Jan 29 2019

Keywords

Comments

n | A306211 after n generations
--+-----------------------------
1 | [1]
2 | [1, 1]
3 | [1, 1, 2]
4 | [1, 1, 2, 2, 1]
5 | [1, 1, 2, 2, 1, 2, 2, 1]
6 | [1, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 1]
7 | [1, 1, 2, 2, 1, 2, 2, 1, 2, 2, 1, 2, 1, 2, 2, 1, 2, 1, 2, 1, 1, 1]

Crossrefs

Cf. A306211.
See A323475 for first differences.

Extensions

a(27)-a(39) from Rémy Sigrist, Jan 29 2019

A306222 Positions of 4's in A306211.

Original entry on oeis.org

60, 84, 93, 96, 123, 132, 135, 147, 150, 156, 162, 185, 194, 197, 209, 212, 218, 224, 232, 235, 241, 247, 249, 283, 292, 295, 307, 310, 316, 322, 330, 333, 339, 345, 347, 366, 369, 375, 381, 383, 396, 439, 448, 451, 463, 466, 472, 478, 486, 489, 495, 501, 503
Offset: 1

Views

Author

Rémy Sigrist, Jan 30 2019

Keywords

Crossrefs

A306223 Positions of 5's in A306211.

Original entry on oeis.org

255, 353, 389, 402, 509, 545, 558, 603, 616, 638, 660, 662, 756, 792, 805, 850, 863, 885, 907, 909, 941, 954, 976, 998, 1000, 1009, 1031, 1033, 1043, 1045, 1049, 1146, 1182, 1195, 1240, 1253, 1275, 1297, 1299, 1331, 1344, 1366, 1388, 1390, 1399, 1421, 1423
Offset: 1

Views

Author

Rémy Sigrist, Jan 30 2019

Keywords

Crossrefs

A323475 Number of new terms added at n-th generation of A306211.

Original entry on oeis.org

1, 1, 1, 2, 3, 5, 9, 15, 24, 39, 62, 98, 156, 247, 390, 611, 953, 1485, 2314, 3613, 5655, 8877, 13970, 22029, 34774, 54904, 86640, 136571, 214992, 338008, 530886, 833391, 1308336, 2055290, 3232624, 5092985, 8040450, 12722620, 20179052
Offset: 0

Views

Author

N. J. A. Sloane, Jan 29 2019

Keywords

Comments

a(0)=1 followed by first differences of A306215.

Crossrefs

A323476 Positions of 3's in A306211.

Original entry on oeis.org

37, 52, 58, 76, 82, 91, 115, 121, 130, 145, 177, 183, 192, 207, 230, 257, 275, 281, 290, 305, 328, 355, 364, 391, 404, 410, 416, 431, 437, 446, 461, 484, 511, 520, 547, 560, 566, 572, 578, 605, 618, 624, 630, 640, 646, 654, 678, 684, 693, 708, 731, 758, 767
Offset: 1

Views

Author

N. J. A. Sloane, Jan 29 2019

Keywords

Crossrefs

Programs

  • C
    See Links section.
  • Mathematica
    seq[n_] := seq[n] = If[n==1, {1}, Join[seq[n-1], Length /@ Split[seq[n-1]]] ];
    Position[seq[26], 3] // Flatten (* Jean-François Alcover, Jul 19 2022 *)

A323477 Successive generations of A306211, in compressed notation.

Original entry on oeis.org

1, 11, 112, 11221, 11221221, 1122122122121, 1122122122121221212111, 1122122122121221212111221212111211113, 1122122122121221212111221212111211113221212111211113211113141
Offset: 1

Views

Author

N. J. A. Sloane, Jan 31 2019

Keywords

Comments

"Compressed" means the separating commas have been omitted. This will only work as long as the terms of A306211 are at most 9. However, we know from Chaffin's work (see A306211) that this is true at least for the first 10228800161220 terms of A306211.

Crossrefs

Cf. A306211, A306215 (lengths), A323478 (increments).

Programs

  • Mathematica
    s[n_] := If[n == 1, {1}, s[n] = Join[s[n-1], Length /@ Split[s[n-1]]]];
    a[n_] := FromDigits[s[n]];
    Array[a, 9] (* Jean-François Alcover, Feb 24 2021 *)

A323478 a(1)=1; thereafter, a(n) = string appended to (n-1)-st generation of A306211 to get the n-th generation.

Original entry on oeis.org

1, 1, 2, 21, 221, 22121, 221212111, 221212111211113, 221212111211113211113141, 221212111211113211113141211113141141111, 22121211121111321111314121111314114111121111314114111114111214
Offset: 1

Views

Author

N. J. A. Sloane, Jan 31 2019

Keywords

Comments

The concatenation of these terms is the sequence A306211 itself.
The concatenation A323477(n-1) followed by a(n) is A323477(n). For example, if n=6, 11221221.22121 = 1122122122121.
The strings a(n) are converging to A323826, the RUNS transform of A306211.

Crossrefs

Cf. A306211, A323477, A306215, A323475 (lengths), A323826 (limiting string).

A323479 Irregular triangle read by rows: T(n,k) (n>=1) = number of occurrences of k in n-th generation of A306211.

Original entry on oeis.org

1, 2, 2, 1, 3, 2, 4, 4, 6, 7, 11, 11, 20, 16, 1, 35, 22, 3, 1, 61, 29, 6, 4, 103, 38, 10, 11, 170, 50, 16, 23, 1, 278, 66, 27, 41, 4, 451, 87, 46, 67, 12, 728, 114, 77, 103, 31, 1165, 149, 127, 152, 71, 1849, 194, 210, 216, 148, 2916, 251, 354, 297, 284, 4577
Offset: 1

Views

Author

N. J. A. Sloane, Jan 31 2019

Keywords

Examples

			Triangle begins:
1,
2,
2, 1,
3, 2,
4, 4,
6, 7,
11, 11,
20, 16, 1,
35, 22, 3, 1,
61, 29, 6, 4,
103, 38, 10, 11,
170, 50, 16, 23, 1,
...
		

Crossrefs

Cf. A306211, A306215 (row sums), A323477, A323481 (first column).

Extensions

a(20)-a(63) from Lars Blomberg, Feb 13 2019

A323481 Number of 1's in n-th generation of A306211.

Original entry on oeis.org

1, 2, 2, 3, 4, 6, 11, 20, 35, 61, 103, 170, 278, 451, 728, 1165, 1849, 2916, 4577, 7165, 11205, 17531, 27467, 43119, 67823, 106854, 168523, 265878, 419356, 660919, 1040546, 1636458, 2571310, 4037926, 6340362, 9959607, 15658964, 24653360, 38881723, 61445514
Offset: 1

Views

Author

N. J. A. Sloane, Jan 31 2019

Keywords

Crossrefs

Cf. A306211.
First column of A323479.

Extensions

More terms from Benjamin Chaffin, Feb 07 2019

A306333 Last term in each generation of A306211.

Original entry on oeis.org

1, 1, 2, 1, 1, 1, 1, 3, 1, 1, 4, 1, 3, 1, 1, 4, 1, 3, 1, 3, 1, 3, 1, 1, 4, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 1, 4, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 1, 4, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3
Offset: 1

Views

Author

Benjamin Chaffin, Feb 08 2019

Keywords

Comments

The first 65 generations of A306211 were computed explicitly. Since the tail of each generation is the RUNS of the tail of the previous generation, if we start with a complete generation then we can get just the tail of some further generations by iterating RUNS on it. This allowed the computation of the remaining 55 terms.
Generations 11, 16, 25, 42, and 75 end in a 4. The number of generations in between those which end in a 4 is thus 4, 8, 16, 32.

Crossrefs

Cf. A306211.
Showing 1-10 of 18 results. Next