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Revision History for A325930

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Showing entries 1-10 | older changes
Total number of colors used in all colored set partitions of [n] where colors of the elements of subsets are distinct and in increasing order and the colors span an initial interval of the color palette.
(history; published version)
#12 by Susanna Cuyler at Tue Dec 15 16:27:54 EST 2020
STATUS

proposed

approved

#11 by Jean-François Alcover at Tue Dec 15 00:56:40 EST 2020
STATUS

editing

proposed

#10 by Jean-François Alcover at Tue Dec 15 00:56:37 EST 2020
MATHEMATICA

b[n_, k_] := b[n, k] = If[n == 0, 1, Sum[b[n - j, k] Binomial[n - 1, j - 1] Binomial[k, j], {j, 1, Min[k, n]}]];

a[n_] := Sum[k Sum[b[n, k-i] (-1)^i Binomial[k, i], {i, 0, k}], {k, 0, n}];

a /@ Range[0, 18] (* Jean-François Alcover, Dec 15 2020, after Alois P. Heinz *)

STATUS

approved

editing

#9 by Alois P. Heinz at Sun Sep 08 18:25:41 EDT 2019
STATUS

editing

approved

#8 by Alois P. Heinz at Sun Sep 08 18:25:23 EDT 2019
LINKS

Alois P. Heinz, <a href="/A325930/b325930.txt">Table of n, a(n) for n = 0..296</a>

#7 by Alois P. Heinz at Sun Sep 08 17:20:25 EDT 2019
MAPLE

b:= proc(n, k) option remember; `if`(n=0, 1, add(b(n-j, k)*

binomial(n-1, j-1)*binomial(k, j), j=1..min(k, n)))

end:

a:= n-> add(k*add(b(n, k-i)*(-1)^i*binomial(k, i), i=0..k), k=0..n):

seq(a(n), n=0..18);

#6 by Alois P. Heinz at Sun Sep 08 17:19:57 EDT 2019
NAME

a

Total number of colors used in all colored set partitions of [n] where colors of the elements of subsets are distinct and in increasing order and the colors span an initial interval of the color palette.

DATA

0, 1, 7, 73, 1075, 21066, 527122, 16313963, 609352653, 26938878757, 1387465470527, 82169954359252, 5534425340505464, 419977314311140561, 35617039966665620743, 3352008343756176938273, 347915661537105210844323, 39607489635223003610928042

OFFSET

0,13

#5 by Alois P. Heinz at Sun Sep 08 17:16:19 EDT 2019
NAME

allocated for Alois P. Heinz

a

DATA

73, 1075, 21066, 527122

OFFSET

0,1

FORMULA

a(n) = Sum_{k=1..n} k * A322670(n,k).

CROSSREFS

Cf. A322670.

KEYWORD

allocated

nonn

AUTHOR

Alois P. Heinz, Sep 08 2019

STATUS

approved

editing

#4 by Alois P. Heinz at Sun Sep 08 17:16:19 EDT 2019
NAME

allocated for Alois P. Heinz

KEYWORD

recycled

allocated

#3 by R. J. Mathar at Fri Aug 23 07:56:38 EDT 2019
STATUS

editing

approved