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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A177670 Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, down, up, up, up, up.

Original entry on oeis.org

1, 1, 70, 34650, 63063000, 304532310180, 3216303433012890, 65316931455144717352
Offset: 0

Views

Author

R. H. Hardin, May 10 2010

Keywords

Crossrefs

Cf. A014608.

A177671 Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, up, down, down, down, down.

Original entry on oeis.org

1, 1, 70, 34650, 63063000, 304935162828, 3227357965784040, 65712161060921061615
Offset: 0

Views

Author

R. H. Hardin, May 10 2010

Keywords

Crossrefs

Cf. A014608.

A177676 Number of permutations of 4 copies of 1..n avoiding adjacent step pattern up, up, up, up, up, up.

Original entry on oeis.org

1, 1, 70, 34650, 63063000, 305540235000, 3246670537110000, 66471564122981413201, 2389990877540259562671201, 140752914446323991227575378870, 12859891096524517937525915077936650, 1745170838822213670914740929271388502150, 339448526227710036385042441267361806617147750
Offset: 0

Views

Author

R. H. Hardin, May 10 2010

Keywords

Links

Crossrefs

Cf. A014608.

Extensions

a(9)-a(12) from Alois P. Heinz, Aug 08 2018

A211311 a(n) = number |fdw(P,(n))| of entangled P-words with s=4.

Original entry on oeis.org

1, 68, 34236, 62758896, 304863598320, 3242854167461280, 66429116436728636640, 2389384600126093124110080
Offset: 1

Views

Author

N. J. A. Sloane, Apr 08 2012

Keywords

Comments

See Jenca and Sarkoci for the precise definition.

Links

Crossrefs

Cf. A014608, A025036.

Formula

From Peter Bala, Sep 05 2012: (Start)
Conjectural e.g.f.: 2 - 1/A(x), where A(x) = sum {n = 0..inf} (4*n)!/24^n*x^n/n! is the e.g.f. for A014608 (also the o.g.f. for A025036).
If true, this leads to the recurrence equation: a(n) = (4*n)!/24^n - sum {k = 1..n-1} (4*k)!/24^k*binomial(n,k)*a(n-k) with a(1) = 1.
(End)
Previous Showing 21-24 of 24 results.

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

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