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.

A375112 Triangle T(n, k), n > 0, k = 0..n-1, read by rows; T(n, k) is the unique m such that A375110(m+1) = n and A375110(m) mod A375110(m+1) = k.

Original entry on oeis.org

1, 3, 2, 5, 7, 4, 10, 9, 14, 6, 12, 16, 18, 8, 11, 21, 23, 20, 30, 15, 13, 26, 25, 32, 36, 40, 17, 22, 28, 34, 38, 42, 44, 19, 24, 27, 47, 49, 51, 53, 46, 72, 31, 33, 29, 56, 58, 60, 55, 74, 82, 90, 37, 35, 48, 63, 65, 62, 76, 84, 92, 98, 41, 39, 50, 57, 68, 67, 78, 86, 94, 100, 104, 108, 43, 52, 59, 64
Offset: 1

Views

Author

Rémy Sigrist, Jul 30 2024

Keywords

Comments

As a flat sequence, this is a permutation of the positive integers with inverse A375113.

Examples

			Triangle T(n, k) begins:
    1;
    3, 2;
    5, 7, 4;
    10, 9, 14, 6;
    12, 16, 18, 8, 11;
    21, 23, 20, 30, 15, 13;
    26, 25, 32, 36, 40, 17, 22;
    28, 34, 38, 42, 44, 19, 24, 27;
    47, 49, 51, 53, 46, 72, 31, 33, 29;
    ...
		

Crossrefs

Cf. A375110, A375113 (inverse).

Programs

  • PARI
    \\ See Links section.

A375111 a(n) = A375110(n) mod A375110(n+1).

Original entry on oeis.org

0, 1, 0, 2, 0, 3, 1, 3, 1, 0, 4, 0, 5, 2, 4, 1, 5, 2, 5, 2, 0, 6, 1, 6, 1, 0, 7, 0, 8, 3, 6, 2, 7, 1, 8, 3, 7, 2, 8, 4, 7, 3, 8, 4, 8, 4, 0, 9, 1, 9, 2, 9, 3, 9, 3, 0, 10, 1, 10, 2, 10, 2, 0, 11, 1, 11, 1, 0, 12, 0, 13, 5, 9, 4, 10, 3, 11, 2, 12, 1, 13, 5, 10
Offset: 1

Views

Author

Rémy Sigrist, Jul 30 2024

Keywords

Examples

			a(42) = A375110(42) mod A375110(43) = 11 mod 8 = 3.
		

Crossrefs

Cf. A375110.

Programs

  • PARI
    \\ See Links section.

A375114 Lexicographically earliest sequence of positive integers such that the pairs (gcd(a(n), a(n+1)), a(n+1)) are all distinct.

Original entry on oeis.org

1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 4, 6, 6, 7, 7, 8, 8, 9, 6, 8, 10, 10, 11, 10, 12, 8, 12, 9, 9, 12, 12, 13, 12, 14, 14, 15, 10, 15, 14, 16, 16, 17, 16, 18, 12, 15, 15, 18, 18, 19, 18, 20, 16, 20, 20, 21, 14, 21, 20, 22, 11, 22, 22, 23, 22, 24, 16, 24, 18, 21
Offset: 1

Views

Author

Rémy Sigrist, Jul 30 2024

Keywords

Comments

The value 1 appears twice; for any v > 1, the value v appears A000005(v) times.

Examples

			The first terms, alongside the corresponding pairs, are:
  n   a(n)  (gcd(a(n), a(n+1)), a(n+1))
  --  ----  ---------------------------
   1     1  (1, 1)
   2     1  (1, 2)
   3     2  (2, 2)
   4     2  (1, 3)
   5     3  (3, 3)
   6     3  (1, 4)
   7     4  (4, 4)
   8     4  (1, 5)
   9     5  (5, 5)
  10     5  (1, 6)
  11     6  (2, 4)
  12     4  (2, 6)
  13     6  (6, 6)
  14     6  (1, 7)
  15     7  (7, 7)
		

Crossrefs

See A375110 for similar sequences.
Cf. A000005.

Programs

  • PARI
    \\ See Links section.

A375115 Lexicographically earliest sequence of positive integers such that the pairs (a(n) AND a(n+1), a(n+1)) are all distinct (where AND denotes the bitwise AND operator).

Original entry on oeis.org

0, 0, 1, 1, 2, 2, 3, 3, 4, 3, 5, 3, 6, 4, 5, 5, 6, 6, 7, 7, 8, 5, 7, 9, 6, 9, 7, 10, 7, 11, 7, 12, 7, 13, 8, 7, 14, 9, 9, 10, 10, 11, 11, 12, 11, 13, 11, 14, 12, 13, 13, 14, 14, 15, 15, 16, 10, 13, 15, 17, 11, 15, 18, 11, 19, 12, 15, 20, 11, 20, 13, 18, 13, 19
Offset: 0

Views

Author

Rémy Sigrist, Jul 30 2024

Keywords

Comments

The value 0 appears twice; for any v > 0, the value v appears A001316(v) times.

Examples

			The first terms, alongside the corresponding pairs, are:
  n   a(n)  (a(n) AND a(n+1), a(n+1))
  --  ----  -------------------------
   0     0  (0, 0)
   1     0  (0, 1)
   2     1  (1, 1)
   3     1  (0, 2)
   4     2  (2, 2)
   5     2  (2, 3)
   6     3  (3, 3)
   7     3  (0, 4)
   8     4  (0, 3)
   9     3  (1, 5)
  10     5  (1, 3)
  11     3  (2, 6)
  12     6  (4, 4)
  13     4  (4, 5)
  14     5  (5, 5)
  15     5  (4, 6)
		

Crossrefs

See A375110 for similar sequences.
Cf. A001316.

Programs

  • PARI
    \\ See Links section.
Showing 1-4 of 4 results.