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 1-5 of 5 results.

A280504 a(n) = A280500(n,A280503(n)).

Original entry on oeis.org

1, 1, 1, 2, 1, 3, 1, 4, 1, 1, 11, 1, 13, 7, 1, 8, 1, 9, 19, 10, 1, 11, 13, 6, 25, 13, 1, 7, 11, 15, 1, 16, 1, 15, 13, 2, 37, 1, 11, 12, 41, 1, 25, 22, 1, 13, 47, 4, 11, 25, 1, 1, 19, 3, 55, 1, 13, 11, 59, 5, 61, 31, 1, 32, 1, 33, 67, 34, 69, 35, 61, 36, 1, 37, 13, 38, 59, 39, 25, 40, 81, 41, 11, 42, 1, 43, 87, 44, 55, 45, 91, 46, 1, 47, 19, 24, 97, 49, 1, 25, 13
Offset: 1

Views

Author

Antti Karttunen, Jan 09 2017

Keywords

Crossrefs

Cf. A044918 (very likely gives the positions of all ones).

Programs

Formula

a(n) = A280500(n,A280503(n)).
Other identities. For all n >= 1:
A048720(a(n), A280503(n)) = n.

A357522 Reverse run lengths in binary expansions of terms of A063037: for n >= 0, a(n) is the unique k such that A063037(1+k) = A056539(A063037(1+n)).

Original entry on oeis.org

0, 1, 2, 3, 6, 5, 4, 7, 8, 11, 10, 9, 16, 17, 18, 15, 12, 13, 14, 19, 32, 23, 22, 21, 24, 31, 28, 27, 26, 29, 30, 25, 20, 33, 42, 49, 48, 43, 44, 47, 50, 41, 34, 37, 38, 53, 52, 39, 36, 35, 40, 51, 46, 45, 74, 75, 84, 65, 58, 59, 64, 85, 86, 63, 60, 57, 66, 83
Offset: 0

Views

Author

Rémy Sigrist, Oct 02 2022

Keywords

Comments

This sequence is a self-inverse permutation of the nonnegative integers.

Examples

			For n = 42:
- A063037(1+42) = 86,
- the binary expansion of 86 is "1010110",
- reversing run lengths yields "1001010",
- this corresponds to 74 = A063037(1+34),
- hence a(42) = 34.
		

Crossrefs

See A357523 for a similar sequence.

Programs

  • PARI
    See Links section.

Formula

a(n) = n iff n = 0 or A044813(1+n) belongs to A044918.

A357523 Reverse run lengths in binary expansions of terms of A166535: for n > 0, a(n) is the unique k such that A166535(k) = A056539(A166535(n)); a(0) = 0.

Original entry on oeis.org

0, 1, 2, 3, 6, 5, 4, 7, 14, 9, 10, 13, 12, 11, 8, 15, 20, 23, 24, 19, 16, 27, 26, 17, 18, 25, 22, 21, 40, 41, 46, 35, 32, 49, 50, 31, 36, 45, 42, 39, 28, 29, 38, 43, 44, 37, 30, 51, 48, 33, 34, 47, 88, 63, 62, 89, 94, 57, 68, 83, 80, 71, 54, 53, 72, 79, 84, 67
Offset: 0

Views

Author

Rémy Sigrist, Oct 02 2022

Keywords

Comments

This sequence is a self-inverse permutation of the nonnegative integers.

Examples

			For n = 42:
- A166535(42) = 50,
- the binary expansion of 50 is "110010",
- reversing run lengths yields "101100",
- this corresponds to 44 = A166535(38),
- hence a(42) = 38.
		

Crossrefs

See A357522 for a similar sequence.

Programs

  • PARI
    See Links section.

Formula

a(n) = n iff n = 0 or A166535(n) belongs to A044918.

A357527 Reverse run lengths in binary expansions of terms of A044813: for n > 0, a(n) is the unique k such that A044813(k) = A056539(A044813(n)); a(0) = 0.

Original entry on oeis.org

0, 1, 2, 4, 3, 5, 7, 6, 8, 12, 11, 10, 9, 13, 23, 18, 20, 22, 15, 21, 16, 19, 17, 14, 24, 36, 29, 33, 35, 26, 34, 32, 31, 27, 30, 28, 25, 37, 55, 44, 47, 49, 52, 54, 39, 53, 51, 40, 50, 41, 48, 46, 42, 45, 43, 38, 56, 82, 63, 68, 76, 79, 81, 58, 69, 73, 80, 78
Offset: 0

Views

Author

Rémy Sigrist, Oct 02 2022

Keywords

Comments

This sequence is a self-inverse permutation of the nonnegative integers.

Examples

			For n = 42:
- A044813(42) = 159,
- the binary expansion of 159 is "10011111",
- reversing run lengths yields "11111001",
- this corresponds to 249 = A044813(52),
- hence a(42) = 52.
		

Crossrefs

See A057164, A357522 and A357523 for similar sequences.

Programs

  • PARI
    See Links section.

Formula

a(n) = n iff n = 0 or A044813(n) belongs to A044918.

A357530 Reverse run lengths in binary expansions of terms of A031443: for n > 0, a(n) is the unique k such that A031443(k) = A056539(A031443(n)); a(0) = 0.

Original entry on oeis.org

0, 1, 2, 3, 4, 11, 8, 7, 6, 9, 12, 5, 10, 13, 14, 45, 41, 31, 18, 38, 28, 21, 22, 27, 37, 36, 26, 23, 20, 29, 39, 17, 32, 42, 46, 35, 25, 24, 19, 30, 40, 16, 33, 43, 47, 15, 34, 44, 48, 49, 170, 165, 150, 115, 54, 161, 146, 111, 58, 136, 101, 68, 81, 88, 123
Offset: 0

Views

Author

Rémy Sigrist, Oct 02 2022

Keywords

Comments

This sequence is a self-inverse permutation of the nonnegative integers.

Examples

			For n = 42:
- A031443(42) = 210,
- the binary expansion of 210 is "11010010",
- reversing run lengths yields "10110100",
- this corresponds to 180 = A031443(33),
- hence a(42) = 33.
		

Crossrefs

See A057164 for a similar sequence.

Programs

  • PARI
    See Links section.

Formula

a(n) = n iff n = 0 or A031443(n) belongs to A044918.
Showing 1-5 of 5 results.