The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A186021 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A186021

a(n) = Bell(n)*(2 - 0^n).
(history; published version)

#82 by Michael De Vlieger at Thu May 02 10:07:02 EDT 2024

STATUS

reviewed

approved

#81 by Joerg Arndt at Thu May 02 09:51:28 EDT 2024

STATUS

proposed

reviewed

#80 by Manfred Boergens at Thu May 02 08:43:27 EDT 2024

STATUS

editing

proposed

#79 by Manfred Boergens at Thu May 02 08:42:02 EDT 2024

COMMENTS

a(n) is the number of collections of subsets of [n] that are pairwise disjoint and cover [n], with [0] = {}. - Manfred Boergens, May 02 2024

STATUS

approved

editing

#78 by Charles R Greathouse IV at Thu Sep 08 08:45:55 EDT 2022

PROG

(MAGMAMagma) [Bell(n)*(2-0^n): n in [0..50]]; // Vincenzo Librandi, Apr 06 2011

Discussion

Thu Sep 08

08:45

OEIS Server: https://oeis.org/edit/global/2944

#77 by Peter Luschny at Thu Mar 24 18:53:31 EDT 2022

STATUS

editing

approved

#76 by Peter Luschny at Thu Mar 24 18:53:20 EDT 2022

MAPLE

A186021List := proc(m) local A, P, n; A := [1, 2]; P := [2];

for n from 1 to m - 2 do P := ListTools:-PartialSums([P[-1], op(P)]);

A := [op(A), P[-1]] od; A end: A186021List(26); # Peter Luschny, Mar 24 2022

STATUS

approved

editing

#75 by Susanna Cuyler at Tue Jun 30 07:59:00 EDT 2020

STATUS

proposed

approved

#74 by Ilya Gutkovskiy at Tue Jun 30 05:46:22 EDT 2020

STATUS

editing

proposed

#73 by Ilya Gutkovskiy at Tue Jun 30 05:35:13 EDT 2020

FORMULA

G.f. A(x) satisfies: A(x) = 1 + (x/(1 - x)) * (1 + A(x/(1 - x))). - Ilya Gutkovskiy, Jun 30 2020

STATUS

approved

editing