FORMULA
Sum_{k>=1} (-1)^(k+1)/a(k) = Pi/8 + 3*log(2)/4. - Amiram Eldar, Jan 26 2024
LINKS
Michael Somos, <a href="/A073189/a073189.txt">Sequences used for indexing triangular or square arrays</a>, 2003.
LINKS
M. Michael Somos, <a href="/A073189/a073189.txt">Sequences used for indexing triangular or square arrays</a>
Discussion
Fri Mar 12
22:24
OEIS Server: https://oeis.org/edit/global/2897
Discussion
Wed May 15
20:11
Randell G Heyman: I have corrected the title of my Arxiv article. In the next 24 hours or so the link will show the article title as Cardinality of a floor function set. At that point OEIS can be changed. Great to pick up that error...thanks.
Mon May 20
18:56
Randell G Heyman: My Arxiv article now shows the word set in the title. So the word can be added in the links section. Thanks.
Thu May 23
14:36
Alois P. Heinz: yes, ok, thank you!
FORMULA
a(n) = floor(b) + floor(n/(floor(b)+1)) where b = (sqrt(4*n+1)-1)/2. - _Randell G. Heyman_, May 08 2019
Discussion
Wed May 15
19:22
Alois P. Heinz: ... made the name clickable ...
19:27
Alois P. Heinz: The comment by Marc le Brun is easy to understand ... [n/k] means floor(n/k). See the example: for n=5: floor(5/1), floor(5/2), floor(5/3), floor(5/4), floor(5/5) gives only 3 distinct values: 1,2,5, and so a(5)=3.
19:29
Alois P. Heinz: The title of your paper is: "Cardinality of a floor function" without the word "set". At least this is what you can see when you follow the link.
