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Revisions by Gordon Hamilton (See also Gordon Hamilton's wiki page)

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Showing entries 1-10 | older changes
Greedy Cantor Dust Partition level 2.
(history; published version)
#22 by Gordon Hamilton at Fri Apr 05 14:33:59 EDT 2024
STATUS

editing

proposed

Discussion
Fri Apr 05
16:11
Jon E. Schoenfield: @Gordon: thanks!

Ihad been so accustomed to seeing “arithmetic progression”, and not “arithmetic sequence”, that I assumed that the latter was a mistake. Later, I was surprised to find that a search of the OEIS for “arithmetic sequence” turned up 123 results. But those OEIS sequence entries are outnumbered by the ones that use “arithmetic progression” by about 11 to 1 …
16:16
Jon E. Schoenfield: @Editors: being a person who doesn’t mind tasks that many would find tedious (perhaps that means I’m just a tedious person?), I would not mind going through the 123 sequences that use the phrase “arithmetic sequence” and replacing it with “arithmetic progression” where the former phrase is clearly being used as a synonym for the latter. Worth doing?
16:17
Jon E. Schoenfield: @Gordon: I’ll try to add the Links entry.
16:25
Jon E. Schoenfield: … but I’m afraid I’m not very good at creating some kinds of Links entries … :-/
#21 by Gordon Hamilton at Fri Apr 05 14:30:48 EDT 2024
COMMENTS

Define the original Cantor Dust sequence to be CCD(1) and this CCD(2). Is it always true for n < m that the number of elements less than k that are in CD(n) will always be equal to or more than the number of elements in CD(m)?

Discussion
Fri Apr 05
14:32
Gordon Hamilton: Jon - I have now defined CD(1) as the Greedy Cantor's Dust Partition (A348636). This sequence is CD(2).
14:33
Gordon Hamilton: I had trouble inputting the following video in the format suggested. https://youtu.be/XJPit6OlM-0
#20 by Gordon Hamilton at Fri Apr 05 14:27:43 EDT 2024
COMMENTS

Start by removing the Greedy Cantor's Dust Partition (A348636) from the set of positive integers. We are left with: 3,6,7,8,9,12,15,16,17,... Now apply the A348636 algorithm on this set. Starting with the lowest term, consecutively partition the positive integers excluding the elements of Cantor's set (level 2) into sets s(1), s(2), s(3), ... so that no arithmetic sequence progression of length 3 exists in a set. When choosing s(k), always choose k as small as possible. a(n) = smallest number in s(n).

EXAMPLE

a(3) = 7, the third integer not in Greedy Cantor's Dust Partition and also not forming an arithmetic sequence progression of length 3 with a(1) and a(2).

a(4) is not 8 because a(2), a(3), 8 would form an arithmetic sequence progression of length 3.

a(4) is not 9 because a(1), a(2), 9 would form an arithmetic sequence progression of length 3.

a(4) = 12, the sixth integer not in Greedy Cantor's Dust Partition and also not forming an arithmetic sequence progression of length 3 with previously admitted integers.

Discussion
Fri Apr 05
14:28
Gordon Hamilton: You are right about arithmetic progression Jon.
#14 by Gordon Hamilton at Sun Mar 31 12:10:07 EDT 2024
STATUS

editing

proposed

#13 by Gordon Hamilton at Sun Mar 31 12:09:56 EDT 2024
NAME

allocated for Gordon HamiltonGreedy Cantor Dust Partition level 2

DATA

3, 6, 7, 12, 15, 16, 19, 30, 33, 34, 39, 42, 43, 46, 55

OFFSET

1,1

COMMENTS

Start by removing the Greedy Cantor's Dust Partition (https://oeis.org/A348636) from the set of positive integers. We are left with: 3,6,7,8,9,12,15,16,17... Now apply the A348636 algorithm on this set. Starting with the lowest term, consecutively partition the positive integers excluding the elements of Cantor's set (level 2) into sets s(1), s(2), s(3), ... so that no arithmetic sequence of length 3 exists in a set. When choosing s(k), always choose k as small as possible. a(n) = smallest number in s(n).

This process can be applied iteratively to create an infinite sequence of Cantor-Dust-like sequences whose intersection is empty and whose union is the set of positive integers.

Define the original Cantor sequence C(1) and this C(2). Is it always true for n<m that the number of elements less than k that are in CD(n) will always be equal or more than the number of elements in CD(m)?

EXAMPLE

a(1) = 3 (the first integer not in Greedy Cantor's Dust Partition (https://oeis.org/A348636).)

a(2) = 6 (the second integer not in Greedy Cantor's Dust Partition.)

a(3) = 7 (the third integer not in Greedy Cantor's Dust Partition and also not forming an arithmetic sequence of length 3 with a(1) and a(2).)

a(4) is not 8 because a(2),a(3),8 would form an arithmetic sequence of length 3.

a(4) is not 9 because a(1),a(2),9 would form an arithmetic sequence of length 3.

a(4) = 12 (the sixth integer not in Greedy Cantor's Dust Partition and also not forming an arithmetic sequence of length 3 with previously admitted integers.)

CROSSREFS
KEYWORD

allocated

nonn

AUTHOR

Gordon Hamilton, Mar 31 2024

STATUS

approved

editing

#12 by Gordon Hamilton at Sun Mar 31 12:09:56 EDT 2024
NAME

allocated for Gordon Hamilton

KEYWORD

recycled

allocated

Starting with the n-th shortest Cartesian line segment, a(n) is the minimal number of consecutive line segments required to make a simple polygon.
(history; published version)
#29 by Gordon Hamilton at Wed Oct 04 08:47:28 EDT 2023
STATUS

editing

proposed

Discussion
Wed Oct 04
08:50
Michel Marcus: why do you want "..."  around the title of your web page ???
#28 by Gordon Hamilton at Wed Oct 04 08:47:19 EDT 2023
COMMENTS

List the possible lengths of line segments achievable by connecting integral coordinates on a Cartesian grid. Starting from the n-th length, a(n) is the smallest number of consecutively greater lengths required to form a simple polygon with all vertices on integral Cartesian coordinates.

EXAMPLE

a(5) = 4 because i) the fifth, sixth, seventh and eighth lengths are sqrt(8), 3, sqrt(10), sqrt(13) and ii) a quadrilateral can be created using edges with these four lengths and iii) the fifth, sixth and seventh lengths alone cannot create a simple polygon with integral Cartesian vertices.

#27 by Gordon Hamilton at Wed Oct 04 08:45:59 EDT 2023
NAME

Starting with the n-th shortest Cartesian line segment, a(n) is the minimal number of consecutive line segments required to make a closed loopsimple polygon.

LINKS

Gordon Hamilton, <a href="https://mathpickle.com/project/rootingfornasa/">"Rooting for NASA"</a>.

STATUS

proposed

editing

#9 by Gordon Hamilton at Sun Oct 01 19:22:00 EDT 2023
STATUS

editing

proposed