The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A093970 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A093970

Number of subsets A of {1..n} such that there are no solutions to a+b+c=d for a,b,c,d in A.
(history; published version)

#14 by Peter Luschny at Wed Oct 07 08:02:42 EDT 2020

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reviewed

approved

#13 by Michel Marcus at Wed Oct 07 07:40:59 EDT 2020

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proposed

reviewed

#12 by Wesley Ivan Hurt at Fri Oct 02 16:04:10 EDT 2020

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editing

proposed

#11 by Wesley Ivan Hurt at Fri Oct 02 16:04:06 EDT 2020

NAME

Number of subsets A of {1,...,n} such that there are no solutions to a+b+c=d for a,b,c,d in A.

COMMENTS

In sumset notation, the sequence gives the number of subsets A of {1,...,n} such that the intersection of A and 3A is empty. Using the Mathematica program, all such subsets can be printed.

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proposed

editing

#10 by Fausto A. C. Cariboni at Fri Oct 02 14:53:16 EDT 2020

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editing

proposed

#9 by Fausto A. C. Cariboni at Fri Oct 02 14:52:42 EDT 2020

LINKS

Fausto A. C. Cariboni, <a href="/A093970/b093970.txt">Table of n, a(n) for n = 0..62</a>

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approved

editing

#8 by Bruno Berselli at Wed Sep 30 09:05:37 EDT 2020

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reviewed

approved

#7 by Joerg Arndt at Wed Sep 30 07:30:19 EDT 2020

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proposed

reviewed

#6 by Fausto A. C. Cariboni at Wed Sep 30 07:20:59 EDT 2020

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editing

proposed

#5 by Fausto A. C. Cariboni at Wed Sep 30 07:20:14 EDT 2020

DATA

1, 2, 4, 6, 11, 21, 31, 55, 99, 145, 252, 430, 620, 1042, 1786, 2597, 4304, 7241, 10374, 17098, 28967, 41444, 68017, 113746, 162204, 268412, 449318, 640341, 1053604, 1764648, 2524852, 4154138, 6968215, 9935216, 16371249, 27594872, 39353636, 64914388, 109205201

EXTENSIONS

a(21)-a(38) from Fausto A. C. Cariboni, Sep 30 2020

STATUS

approved

editing