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 157 results. Next

A113676 Number of elements of rows of Golomb's sequence A001462, with one less 2, interpreted as triangle: Start with first row 1. The row sum of row n-1 gives the number of elements taken from A001642 (one less 2) of row n.

Original entry on oeis.org

1, 1, 2, 6, 27, 234, 6202, 1084009, 4362192095
Offset: 1

Views

Author

Floor van Lamoen and Paul D. Hanna, Nov 06 2005

Keywords

Comments

a(n+1) gives row sum of row n of this triangle.
Conjecture: a(n) for n>1 gives first differences of Lionel Levine's sequence A014644(n) for n>=3.
Conjecture: Final elements of the rows form A014644 except for duplicate 2.

Examples

			The triangle begins
  1;
  2;
  3,3;
  4,4,4,5,5,5;
  ...
Row 4: [4,4,4,5,5,5] is generated from row 3: [3,3] because there are (3) 4's and (3) 5's in row 4.
		

A001463 Partial sums of A001462; also a(n) is the last occurrence of n in A001462.

Original entry on oeis.org

1, 3, 5, 8, 11, 15, 19, 23, 28, 33, 38, 44, 50, 56, 62, 69, 76, 83, 90, 98, 106, 114, 122, 131, 140, 149, 158, 167, 177, 187, 197, 207, 217, 228, 239, 250, 261, 272, 284, 296, 308, 320, 332, 344, 357, 370, 383, 396, 409, 422, 436, 450, 464, 478, 492, 506, 521, 536, 551, 566, 581, 596
Offset: 1

Views

Author

Keywords

Comments

Vardi gives several identities satisfied by A001463 and this sequence.

References

  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Programs

Formula

a(n) is asymptotic to tau^(1-tau)*n^tau where tau is the golden ratio, tau=(1+sqrt(5))/2. More precisely, a(n)= tau^(1-tau)*n^tau + c*n^(1/tau)+0(n^(1/tau)) where c is a constant around 0.6. Is there any known value for c? - Benoit Cloitre, Oct 29 2002

A109512 Integers which are not the sum of n and A001462(n).

Original entry on oeis.org

0, 1, 3, 6, 9, 13, 17, 22, 27, 32, 38, 44, 50, 57, 64, 71, 78, 86, 94, 102, 110, 119, 128, 137, 146, 156, 166, 176, 186, 196, 207, 218, 229, 240, 251, 263, 275, 287, 299, 311, 324, 337, 350, 363, 376, 389, 403, 417, 431, 445, 459, 473, 488, 503, 518, 533, 548
Offset: 0

Views

Author

Keywords

Comments

Terms computed by Robert G. Wilson v.

Examples

			Let N=succession of the natural numbers, G=Golomb self-describing sequence, S=sum of n and according G(n):
N=1.2.3.4.5..6..7..8..9.10.11.12.13.14.15.16.17.18.19.20.21.22
G=1,2,2,3,3,.4,.4,.4,.5,.5,.5,.6,.6,.6,.6,.7,.7,.7,.7,.8,.8,.8
S=2.4.5.7.8.10.11.12.14.15.16.18.19.20.21.23.24.25.26.28.29.30
Integers not in S (0,1,3,6,9,13,17,22...) form the sequence.
		

Programs

  • Mathematica
    a[1] = 1; a[n_] := a[n] = 1 + a[n - a[a[n - 1]]]; Do[ a[n], {n, 10^5}]; h = Complement[ Range[100000 + a[10^5]], Table[n + a[n], {n, 10000}]] t = Table[n + Sum[PrimePi[k], {k, 1, n}], {n, 0, 1200}]

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

A319434 Take Golomb's sequence A001462 and shorten all the runs by 1.

Original entry on oeis.org

2, 3, 4, 4, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19
Offset: 1

Views

Author

N. J. A. Sloane, Oct 02 2018

Keywords

Comments

In other words, apply Lenormand's "raboter" transformation (see A318921) to A001462.
Each value of n (n >= 2) appears exactly A001462(n)-1 times.
There should be a simple formula for a(n), just as there is for Golomb's sequence. - N. J. A. Sloane, Nov 15 2018. After 10000 terms, a(n) seems to be growing like constant*n^0.640. - N. J. A. Sloane, Jun 04 2021

Examples

			Golomb's sequence begins 1, 2,2, 3,3, 4,4,4, 5,5,5, ...
and we just shorten each run by one term, getting 2, 3, 4,4, 5,5, ...
		

Crossrefs

Formula

a(n) = A001462(A001462(A001462(n) + n) + n). - Alan Michael Gómez Calderón, Aug 14 2025

Extensions

More terms from Rémy Sigrist, Oct 04 2018

A321020 A hybrid of Kolakoski's sequence A000002 and Golomb's sequence A001462: if A001462(n) is odd replace it with 1, if even with 2.

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Nov 11 2018

Keywords

Comments

This is A000002 rewritten so the run lengths are given by A001462.
The companion sequence, A001462 rewritten so the run lengths are given by A000002, seems to be A156253.
Note that Kolakoski's sequence A000002 and Golomb's sequence A001462 have very similar definitions, although the asymptotic behavior of A001462 is well-understood, while that of A000002 is a mystery. The asymptotic behavior of the two hybrids A156253 and A321020 might be worth investigating.

Crossrefs

Programs

  • PARI
    a = vector(84, k, k); for (i=1, oo, for (j=1, a[i], a[n++] = i; print1 (2-(i%2) ", "); if (n==#a, break(2)))) \\ Rémy Sigrist, Nov 12 2018

A377862 A variant of Golomb's sequence (A001462): the n-th digit of the sequence gives the number of times n appears, with a(1) = 1 and a(2) = 2.

Original entry on oeis.org

1, 2, 2, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 19, 19
Offset: 1

Views

Author

Rémy Sigrist, Nov 10 2024

Keywords

Comments

This sequence is a base-10 variant of A167500.
Numbers corresponding to positions of zeros do not appear in the sequence.
This sequence first differ from A001462 for n = 169: a(169) = 31 whereas A001462(169) = 29.

Crossrefs

Cf. A001462, A087739, A167500, A377863 (missing numbers), A377896.

Programs

  • PARI
    \\ See Links section.

A306230 Lexicographically earliest sequence of distinct positive terms such that for any n > 0, G(n) <> G(a(n)) (where G denotes the Golomb's sequence A001462).

Original entry on oeis.org

2, 1, 4, 3, 6, 5, 9, 10, 7, 8, 12, 11, 16, 17, 18, 13, 14, 15, 20, 19, 24, 25, 26, 21, 22, 23, 29, 30, 27, 28, 34, 35, 36, 31, 32, 33, 39, 40, 37, 38, 45, 46, 47, 48, 41, 42, 43, 44, 51, 52, 49, 50, 57, 58, 59, 60, 53, 54, 55, 56, 63, 64, 61, 62, 70, 71, 72
Offset: 1

Views

Author

Rémy Sigrist, Jan 30 2019

Keywords

Comments

This sequence is a self-inverse permutation of the natural numbers.
For any n > 0, let b(n) = a(n) - n; the sequence b is unbounded.

Examples

			The first terms of the sequence, alongside G, are:
  n   a(n)  G(n)
  --  ----  ----
   1     2     1
   2     1     2
   3     4     2
   4     3     3
   5     6     3
   6     5     4
   7     9     4
   8    10     4
   9     7     5
  10     8     5
  11    12     5
  12    11     6
  13    16     6
  14    17     6
  15    18     6
  16    13     7
  17    14     7
  18    15     7
  19    20     7
  20    19     8
		

Crossrefs

See A306229 for a similar sequence.
Cf. A001462.

Programs

  • PARI
    See Links section.

A143124 Triangle read by rows, sum {j=k..n}, A001462(j), 1<=k<=n, A001462 = Golomb's sequence.

Original entry on oeis.org

1, 3, 2, 5, 4, 2, 8, 7, 5, 3, 11, 10, 8, 6, 3, 15, 14, 12, 10, 7, 4, 19, 18, 16, 14, 11, 8, 4, 23, 22, 20, 18, 15, 12, 8, 4, 28, 27, 25, 23, 20, 17, 13, 9, 5, 33, 32, 30, 28, 25, 22, 1814, 10, 5, 38, 37, 35, 3330, 27, 23, 19, 15, 10, 5, 44, 43, 41, 39, 36, 33, 29, 25, 21, 16, 11, 6
Offset: 1

Views

Author

Keywords

Comments

Right border of the triangle = Golomb's sequence, A014262.
Left border = A001463.
Row sums = A143125: (1, 5, 11, 23, 38, 62, 90, 122,...).

Examples

			First few rows of the triangle =
1;
3, 2;
5, 4, 2;
8, 7, 5, 3;
11, 10, 8, 6, 3;
15, 14, 12, 10, 7, 4;
19, 18, 16, 14, 11, 8, 4;
23, 22, 20, 18, 15, 12, 8, 4;
28, 27, 25, 23, 20, 17, 13, 9, 5;
...
T(5,3) = 8 = (3 + 3 + 2) where Golomb's sequence = (1, 2, 2, 3, 3, 4, 4, 4,...).
		

Crossrefs

Formula

Triangle read by rows, T(n,k) = sum {j=k..n} A001462(j), 1<=k<=n; where A001462 = (1, 2, 2, 3, 3, 4, 4,...). A000012 * (A001462 * 0^(n-k)) * A000012
Showing 1-10 of 157 results. Next