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.

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A089402 Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutation A089864.

Original entry on oeis.org

1, 1, 2, 3, 8, 22, 68, 217, 720, 2438, 8412, 29414, 104048, 371516, 1337352, 4847637, 17679264, 64823110, 238820780, 883634026, 3282065072, 12233141908, 45741298616, 171529836218, 644952132448, 2430973304732, 9183676744088
Offset: 0

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Author

Antti Karttunen, Nov 29 2003

Keywords

Comments

The number of orbits to which the corresponding automorphism(s) partitions the set of A000108(n) binary trees with n internal nodes.

Programs

Formula

a(n) = (A000108(n)+A089408(n))/2

A089407 Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutation A089859/A089863.

Original entry on oeis.org

1, 1, 1, 2, 4, 11, 34, 109, 360, 1219, 4206, 14708, 52024, 185758, 668676, 2423821, 8839632, 32411555, 119410390, 441817020, 1641032536, 6116570954, 22870649308, 85764918130, 322476066224, 1215486652366, 4591838372044, 17383387914792
Offset: 0

Views

Author

Antti Karttunen, Nov 29 2003

Keywords

Comments

The number of orbits to which the corresponding automorphism(s) partitions the set of A000108(n) binary trees with n internal nodes.

Programs

  • Scheme
    (define (A089407 n) (if (< n 2) 1 (* (/ 1 4) (+ (A000108 n) (A089408 n) (if (= 3 (modulo n 4)) (* 2 (A000108 (/ (- n 3) 4))) 0)))))

Formula

a(0) = a(1) = 1, a(n) = (1/4)*(A000108(n) + A089408(n) + (if (n == 3 mod 4) 2*A000108((n-3)/4)))

A089412 Least common multiple of all cycle sizes in range [A014137(n-1)..A014138(n-1)] of permutation A074683/A074684.

Original entry on oeis.org

1, 1, 2, 5, 18, 84, 2793, 211123440, 140826255570, 213340617315, 156232599082560
Offset: 0

Views

Author

Antti Karttunen, Nov 29 2003

Keywords

A089413 Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutation A071655/A071656.

Original entry on oeis.org

1, 1, 1, 2, 2, 4, 4, 5, 5, 11, 11, 17, 11, 21, 17, 30, 22, 52, 24, 74, 36
Offset: 0

Views

Author

Antti Karttunen, Nov 29 2003

Keywords

Comments

The number of orbits to which the corresponding automorphism(s) partitions the set of A000108(n) binary trees with n internal nodes.

Crossrefs

Bisections: A089409, A089416. Cf. A089411.

A127278 Number of fixed points in range [A014137(n-1)..A014138(n-1)] of permutation A126313/A126314.

Original entry on oeis.org

1, 1, 0, 2, 4, 2, 0, 4, 0, 1, 0, 0, 0
Offset: 0

Views

Author

Antti Karttunen, Jan 16 2007

Keywords

Crossrefs

Fixed points themselves are given in A127306. Cf. A127282.

A127279 Maximum cycle size in range [A014137(n-1)..A014138(n-1)] of permutation A126313/A126314.

Original entry on oeis.org

1, 1, 2, 3, 4, 8, 10, 32, 79, 176, 612, 644, 8547
Offset: 0

Views

Author

Antti Karttunen, Jan 16 2007

Keywords

Crossrefs

A127383 Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutation A127377/A127378.

Original entry on oeis.org

1, 1, 1, 2, 6, 15, 46, 141, 446, 1427, 4722, 15884, 54224, 187380
Offset: 0

Views

Author

Antti Karttunen, Jan 16 2007

Keywords

Crossrefs

A130918 Simple self-inverse permutation of natural numbers: List each block of A000108(n) numbers from A014137(n-1) to A014138(n-1) in reverse order.

Original entry on oeis.org

0, 1, 3, 2, 8, 7, 6, 5, 4, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 196, 195, 194, 193, 192
Offset: 0

Views

Author

Antti Karttunen, Jun 11 2007

Keywords

Comments

In principle this involution is the signature permutation of yet another Catalan automorphism. However, the question remains what is the most "natural" way to create such an automorphism acting e.g. on S-expressions (i.e. rooted plane binary trees), which would produce this sequence as its signature permutation.

Crossrefs

Inverse: A130918. Cf. A054429, A057163. The number of cycles and the number of fixed points in range [A014137(n-1)..A014138(n-1)] of this permutation are given by A130380 and A036987.

Programs

Formula

a(0)=0, a(n) = A014138(A072643(n)-1) - A082853(n).

A081152 Number of even cycles in range [A014137(2n)..A014138(2n)] of permutation A057505/A057506.

Original entry on oeis.org

0, 1, 6, 37, 212, 1226, 6822, 38081, 215414
Offset: 0

Views

Author

Wouter Meeussen and Antti Karttunen, Mar 10 2003

Keywords

Crossrefs

Formula

a(n) = A081150(2n+1) = A081159(n)+A081161(n)+A081163(n).

A081156 Number of odd cycles in range [A014137(2n)..A014138(2n)] of permutation A057505/A057506, with fixed-points of both A057163 and A057164.

Original entry on oeis.org

1, 1, 2, 3, 6, 12, 20, 59, 120
Offset: 0

Views

Author

Keywords

Comments

See comment at A080973.

Crossrefs

Formula

a(n) = A081155(2n+1) = A000108(n) - 2*A081163(n).
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