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.

A338247 Inverse permutation to A338245.

Original entry on oeis.org

0, 1, 4, 2, 3, 13, 11, 12, 7, 5, 6, 10, 8, 9, 40, 38, 39, 34, 32, 33, 37, 35, 36, 22, 20, 21, 16, 14, 15, 19, 17, 18, 31, 29, 30, 25, 23, 24, 28, 26, 27, 121, 119, 120, 115, 113, 114, 118, 116, 117, 103, 101, 102, 97, 95, 96, 100, 98, 99, 112, 110, 111, 106
Offset: 0

Views

Author

Rémy Sigrist, Oct 18 2020

Keywords

Links

Crossrefs

Cf. A338245.

A338246 Nonpositive values in A117966, in order of appearance and negated.

Original entry on oeis.org

0, 1, 3, 2, 4, 9, 8, 10, 6, 5, 7, 12, 11, 13, 27, 26, 28, 24, 23, 25, 30, 29, 31, 18, 17, 19, 15, 14, 16, 21, 20, 22, 36, 35, 37, 33, 32, 34, 39, 38, 40, 81, 80, 82, 78, 77, 79, 84, 83, 85, 72, 71, 73, 69, 68, 70, 75, 74, 76, 90, 89, 91, 87, 86, 88, 93, 92, 94
Offset: 0

Views

Author

Rémy Sigrist, Oct 18 2020

Keywords

Comments

This sequence is a self-inverse permutation of the nonnegative integers (the offset has been set to 0 so as to get a permutation).

Examples

			A117966 = 0, 1, -1, 3, 4, 2, -3, -2, -4, 9, 10, 8, 12, 13, 11, 6, 7, 5, -9, ...
We keep:  0,     1,           3,  2,  4,                                 9, ...

Links

Crossrefs

Cf. A003462 (fixed points), A117966, A157671, A338245.

Programs

  • PARI
    A117966(n) = subst(Pol(apply(x->if(x == 2, -1, x), digits(n, 3)), 'x), 'x, 3)
print (-select(v -> v<=0, apply(A117966, [0..188])))

Formula

a(0) = 0.
a(n) = -A117966(A157671(n)) for any n > 0.
a(n) = n iff n belongs to A003462.

A338248 Nonnegative values in A053985, in order of appearance.

Original entry on oeis.org

0, 1, 4, 5, 2, 3, 16, 17, 14, 15, 20, 21, 18, 19, 8, 9, 6, 7, 12, 13, 10, 11, 64, 65, 62, 63, 68, 69, 66, 67, 56, 57, 54, 55, 60, 61, 58, 59, 80, 81, 78, 79, 84, 85, 82, 83, 72, 73, 70, 71, 76, 77, 74, 75, 32, 33, 30, 31, 36, 37, 34, 35, 24, 25, 22, 23, 28, 29
Offset: 0

Views

Author

Rémy Sigrist, Oct 18 2020

Keywords

Comments

This sequence is a self-inverse permutation of the nonnegative integers (the offset has been set to 0 so as to get a permutation).
There are only two fixed points: a(0) = 0 and a(1) = 1.

Examples

			A053985 = 0, 1, -2, -1, 4, 5, 2, 3, -8, -7, -10, -9, -4, -3, -6, -5, 16, 17, ...
We keep:  0, 1,         4, 5, 2, 3,                                  16, 17, ...

Links

Crossrefs

See A338245 for a similar sequence.
Cf. A053738, A053985, A338249.

Programs

  • PARI
    A053985(n) = fromdigits(binary(n), -2)
print (select(v -> v>=0, apply(A053985, [0..109])))

Formula

a(0) = 0.
a(n) = A053985(A053738(n)) for any n > 0.

A338251 Nonnegative values in A317050, in order of appearance.

Original entry on oeis.org

0, 1, 2, 3, 5, 4, 8, 9, 7, 6, 10, 11, 13, 12, 20, 21, 19, 18, 14, 15, 17, 16, 32, 33, 31, 30, 34, 35, 37, 36, 28, 29, 27, 26, 22, 23, 25, 24, 40, 41, 39, 38, 42, 43, 45, 44, 52, 53, 51, 50, 46, 47, 49, 48, 80, 81, 79, 78, 82, 83, 85, 84, 76, 77, 75, 74, 70, 71
Offset: 0

Views

Author

Rémy Sigrist, Oct 18 2020

Keywords

Comments

This sequence is a permutation of the nonnegative integers, with inverse A338253 (the offset has been set to 0 so as to have a permutation).

Examples

			A338251 = 0, 1, -1, -2, 2, 3, 5, 4, -4, -3, -5, -6, -10, -9, -7, -8, 8, ...
We keep:  0, 1,         2, 3, 5, 4,                                  8, ...

Links

Crossrefs

See A338245 and A338248 for similar sequences.
Cf. A053738, A193652, A317050, A338252, A338253.

Programs

  • PARI
    A317050(n) = fromdigits(binary(bitxor(n, n>>1)), -2)
print (select(v -> v>=0, apply(A317050, [0..109])))

Formula

a(0) = 0.
a(n) = A317050(A053738(n)) for any n > 0.
a(n) = n iff n belongs to A193652.
Showing 1-4 of 4 results.

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