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A322881 Number of set partitions of [n] such that the maximal absolute difference between the least elements of consecutive blocks equals eight. 2

%I

%S 0,1,131,2837,36733,392532,3862958,36745885,346270455,3276723147,

%T 31384368348,305668217577,3035028866706,30761374688048,

%U 318435571825333,3367380704425616,36376061350280633,401367264163810215,4522617803400779891,52030240381937090624

%N Number of set partitions of [n] such that the maximal absolute difference between the least elements of consecutive blocks equals eight.

%H Alois P. Heinz, <a href="/A322881/b322881.txt">Table of n, a(n) for n = 8..580</a>

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Partition_of_a_set">Partition of a set</a>

%F a(n) = A287258(n) - A287257(n).

%p b:= proc(n, k, m, l) option remember; `if`(n<1, 1,

%p `if`(l-n>k, 0, b(n-1, k, m+1, n))+m*b(n-1, k, m, l))

%p end:

%p A:= (n, k)-> b(n-1, min(k, n-1), 1, n):

%p a:= n-> (k-> A(n, k)-A(n, k-1))(8):

%p seq(a(n), n=8..30);

%Y Column k=8 of A287215.

%Y Cf. A287257, A287258.

%K nonn

%O 8,3

%A _Alois P. Heinz_, Dec 29 2018

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Last modified August 13 19:30 EDT 2020. Contains 336451 sequences. (Running on oeis4.)