The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A332748 The number of permutations of {1,1,1,2,2,2,...,n,n,n} with the property that b(1) >= b(2) >= ... >= b(n) (Three k's are skipped by b(k) for k=1..n). 2
 1, 1, 4, 18, 124, 738, 7464, 55890, 668778, 7030210 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS EXAMPLE In case of n = 1.      |           | b(1) -----+-----------+------    1 | [1, 1, 1] | [0] * In case of n = 2.      |                    | b(1),b(2) -----+--------------------+----------    1 | [2, 2, 2, 1, 1, 1] | [0, 0]    2 | [2, 1, 2, 1, 2, 1] | [1, 1]    3 | [1, 2, 1, 2, 1, 2] | [1, 1]    4 | [1, 1, 1, 2, 2, 2] | [0, 0] In case of n = 3.      |                             | b(1),b(2),b(3) -----+-----------------------------+---------------    1 | [3, 3, 3, 2, 2, 2, 1, 1, 1] | [0, 0, 0]    2 | [3, 3, 3, 2, 1, 2, 1, 2, 1] | [1, 1, 0]    3 | [3, 3, 3, 1, 2, 1, 2, 1, 2] | [1, 1, 0]    4 | [3, 3, 3, 1, 1, 1, 2, 2, 2] | [0, 0, 0]    5 | [3, 2, 1, 3, 2, 1, 3, 2, 1] | [2, 2, 2]    6 | [3, 1, 2, 3, 1, 2, 3, 1, 2] | [2, 2, 2]    7 | [1, 3, 3, 3, 1, 2, 2, 2, 1] | [3, 0, 0]    8 | [2, 3, 1, 2, 3, 1, 2, 3, 1] | [2, 2, 2]    9 | [1, 3, 2, 1, 3, 2, 1, 3, 2] | [2, 2, 2]   10 | [2, 1, 3, 2, 1, 3, 2, 1, 3] | [2, 2, 2]   11 | [1, 2, 3, 1, 2, 3, 1, 2, 3] | [2, 2, 2]   12 | [2, 2, 2, 3, 3, 3, 1, 1, 1] | [0, 0, 0]   13 | [1, 1, 1, 3, 3, 3, 2, 2, 2] | [0, 0, 0]   14 | [1, 2, 2, 2, 1, 3, 3, 3, 1] | [3, 0, 0]   15 | [2, 2, 2, 1, 1, 1, 3, 3, 3] | [0, 0, 0]   16 | [2, 1, 2, 1, 2, 1, 3, 3, 3] | [1, 1, 0]   17 | [1, 2, 1, 2, 1, 2, 3, 3, 3] | [1, 1, 0]   18 | [1, 1, 1, 2, 2, 2, 3, 3, 3] | [0, 0, 0] * (strongly decreasing) CROSSREFS Cf. A059108, A261516 (strongly decreasing), A322178, A332752. Sequence in context: A292500 A228065 A317377 * A215691 A073511 A108704 Adjacent sequences:  A332745 A332746 A332747 * A332749 A332750 A332751 KEYWORD nonn,more AUTHOR Seiichi Manyama, Feb 21 2020 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 20 18:08 EDT 2021. Contains 343135 sequences. (Running on oeis4.)