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Entries in the The On-Line Encyclopedia of Integer Sequences give at most three lines of terms
(about 200 characters - a carry-over
from the days when the database was on punched cards).
Often one wants more terms than this, so many sequences now have
"b-files", giving 10000 or more terms.
The format for a b-file is:
1 2
2 3
3 5
4 7
5 11
6 13
7 17
8 19
etc.
with one line per entry.
This is a list of pairs "n a(n)",
where n starts at the correct offset for the sequence
and a(n) is the n-th term.
Please send the b-file by email (as an attachment) to
njas@research.att.com.
As subject line, say something like "b-file for A123456"
The name of the b-file for A123456 (say) would be b123456.txt
The above example is the file
b000040.txt
for the primes, A000040.
For other examples see the b-files for the
Fibonacci numbers A000045,
A000594, etc.
Remarks
-
The values of n should start with the offset of the sequence
(this is the first number in the %O line).
-
Lines beginning with # are comments lines and are ignored.
Blank lines are also ignored.
-
The b-file for a triangle of numbers is obtained by "flattening"
the triangle - for example, see the
b-file
for Pascal's triangle
A007318
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When you send a b-file, please also send a link to it,
which will be added to the sequence entry.
Examples:
The format for the b-file has been changed
to the following shorter versions! Feb 15 2008
%H A001620 T. D. Noe, <a href="b001620.txt">Table of n, a(n) for n=0..2000</a>
%H A139080 M. F. Hasler, <a href="b139080.txt">Table of n, a(n) for n=1,...,10000</a>.
%H A047999 T. D. Noe, <a href="b047999.txt">Rows n=0..50 of triangle, flattened</a>
You could include this %H line in the email which has the b-file
as an attachment.
Or you could include it in the
web page
if you are sending in other comments for the same sequence.
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Each pair n, a(n) should be on a single line, even if a(n) is very large.
But a(n) should not have more than about 1000 digits, or some
of the programs will fail.
For an example with large entries, see the
b-file
for A121263.
-
If possible, each
line in the b-file should end with the single line-feed (LF) character,
rather than the two-character carriage-return line-feed (CR LF) used
in DOS files. (This may not be possible with certain operating systems.)
Again, if possible please use spaces rather than tabs to separate the two numbers on each line.
-
If possible, send the b-file using plain text format!
IMPORTANT:
Thousands of people use the sequence database every day.
Please take great care that
what you send is absolutely correct.
The standards are those of a mathematics reference work.
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