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 1-4 of 4 results.

A064569 Quotients A005132(k)/k for k=A064568(n).

Original entry on oeis.org

1, 2, 2, 3, 2, 2, 2, 2, 1, 2, 1, 4, 1, 2, 5, 3, 2, 3, 4, 3, 4, 3, 1, 1, 1, 1, 4, 1, 3, 5
Offset: 1

Views

Author

N. J. A. Sloane, Oct 16 2001

Keywords

Comments

No more terms < 6.46*10^13. - James Ewens, Sep 27 2024

Examples

			From _Seiichi Manyama_, May 02 2020: (Start)
Let b(n) = A005132(A064568(n)).
   n | A064568(n) |    b(n) | a(n)
-----+------------+---------+------
   1 |          1 |       1 |    1
   2 |          3 |       6 |    2
   3 |         11 |      22 |    2
   4 |         21 |      63 |    3
   5 |         39 |      78 |    2
   6 |         76 |     152 |    2
   7 |        248 |     496 |    2
   8 |        844 |    1688 |    2
   9 |       1520 |    1520 |    1
  10 |       2752 |    5504 |    2
  11 |       9317 |    9317 |    1
  12 |      17223 |   68892 |    4
  13 |      31221 |   31221 |    1
  14 |      57071 |  114142 |    2
  15 |      99741 |  498705 |    5
  16 |     589932 | 1769796 |    3 (End)

Links

Crossrefs

Cf. A005132, A064568, A331659, A333548.

Extensions

a(1)=1 inserted by Seiichi Manyama, May 02 2020
a(22)-a(30) added by James Ewens, Sep 27 2024

A333548 Numbers k such that A005132(k-1) = k.

Original entry on oeis.org

3, 11, 39, 248, 844, 2752, 57071, 58056875
Offset: 1

Views

Author

N. J. A. Sloane, May 01 2020

Keywords

Comments

Subtracting 1 from k gives the index of a term A005132(k-1) = k in Recamán's sequence A005132 such that subtracting k would reach 0. This is not permitted, so we must add k instead, obtaining A005132(k) = 2*k.
If A005132(k-1) = k, A005132(k) = 2*k. The converse is not always true. For example, A005132(75) = 228 and A005132(76) = 228 - 76 = 152. - Seiichi Manyama, May 02 2020

Examples

			A005132(10)=11, so 11 is a term (and A005132(11)=22).

Links

Crossrefs

Cf. A005132, A064568, A064569, A187921, A187922, A331659.

Programs

Extensions

a(8) from Chai Wah Wu, May 02 2020

A330791 Values of k such that A005132(k) (the k-th number in the Recamán sequence) divides k.

Original entry on oeis.org

1, 4, 16, 58, 624, 1520, 8346, 9317, 31221, 240048, 297624, 778144, 2757880, 4670769, 7654224, 24206384, 54806653, 76521364, 260393208, 846807152, 19488644316, 58671741024, 105968380189, 140689013614, 325374626148, 535755688021, 1404720439053, 3116427665348, 3883018238329, 16166305650060
Offset: 1

Views

Author

Jud McCranie, Jan 23 2020

Keywords

Comments

The intersection of A064568 and this sequence are the values of k such that A005132(k)=k.
No more terms < 6.46*10^13. - James Ewens, Sep 28 2024

Examples

			A005132(4)=2 and 2 divides 4, so 4 is in the sequence.

Links

Crossrefs

Cf. A005132, A330788, A330789, A064568.

Extensions

a(26)-a(30) from James Ewens, Sep 28 2024

A331659 Fixed points in the Recamán sequence; k such that A005132(k) = k.

Original entry on oeis.org

0, 1, 1520, 9317, 31221, 325374626148, 535755688021, 1404720439053, 3883018238329, 16166305650060
Offset: 1

Views

Author

Jud McCranie, Jan 23 2020

Keywords

Comments

This is the intersection of A064568 and A330791.
No more terms < 6.46*10^13. - James Ewens, Sep 27 2024

Examples

			A005132(1520) = 1520, so 1520 is in the sequence.

Links

Crossrefs

Cf. A005132, A064568, A330791.

Extensions

a(7)-a(10) from James Ewens, Sep 27 2024
Showing 1-4 of 4 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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