cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-4 of 4 results.

A264483 First column of A264482.

Original entry on oeis.org

1, 1, 1, 1, 1, 5, 1, 5, 1, 11, 7, 1, 11, 7, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 29, 1217, 1213, 1213, 11, 11, 44879, 44873, 44867, 13, 525337, 250297, 127571, 127571, 13639459, 17, 2477591, 2477591, 2477591, 9339217, 17, 17
Offset: 1

Views

Author

Max Barrentine, Nov 14 2015

Keywords

Comments

Initial term of the set of n coprime numbers that minimizes the difference between first and last terms, and then minimizes the average of the terms.
Does every prime greater than 3 occur in this sequence?

Crossrefs

Cf. A264482.

Extensions

a(32)-a(38) from Max Barrentine, Apr 26 2016
a(39)-a(46) from Max Barrentine, Jun 23 2016

A261987 Triangle read by rows: row n lists the set of n coprime composite numbers that minimizes the difference between first and last terms, and then minimizes the average of the terms.

Original entry on oeis.org

4, 8, 9, 25, 26, 27, 91, 92, 93, 95, 115, 116, 117, 119, 121, 527, 529, 531, 532, 533, 535, 527, 529, 531, 533, 535, 536, 539, 1331, 1333, 1334, 1337, 1339, 1341, 1343, 1345, 1331, 1333, 1334, 1337, 1339, 1341, 1343, 1345, 1349
Offset: 1

Views

Author

Max Barrentine, Oct 02 2015, Nov 03 2015, Nov 05 2015

Keywords

Comments

The minimal set of the (k+n)th row is determined by the minimal k-tuple coprime to the n-th primorial, where every prime <= to the n-th prime must be a factor of some number in the set. E.g., the sixth row must consist of numbers congruent to 5, 7, 11 and 13 mod 6, as well as one term with a factor of 2 and another with a factor of 3.
In cases where multiple k-tuples satisfy the definition, the lexicographically earliest solution is chosen.

Examples

			4;
8,   9;
25,  26,  27;
91,  92,  93,  95;
115, 116, 117, 119, 121;
527, 529, 531, 532, 533, 535;
...

Links

Crossrefs

Subsequence of A002808.
First column is A262042.
Cf. A264482.

A260652 The minimal difference between the first and last terms of a set of n coprime numbers.

Original entry on oeis.org

0, 1, 2, 4, 6, 8, 12, 14, 18, 20, 24, 30, 32, 36, 38, 42, 48, 50, 56, 60, 62, 68, 72, 78, 84, 86, 90, 94, 98, 102, 108, 114, 120, 126, 130, 136, 140, 146, 150, 156, 158, 162, 168, 174, 180, 182
Offset: 1

Views

Author

Max Barrentine, Nov 25 2015

Keywords

Comments

a(n>3) <= prime(n-2) + 1.

Links

Crossrefs

Cf. A261987, A264482.

Extensions

a(33)-a(39) from Max Barrentine, Apr 26 2016
a(40)-a(46) from Max Barrentine, Jun 23 2016

A262042 First column of A261987.

Original entry on oeis.org

4, 8, 25, 91, 115, 527, 527, 1331, 1331, 4301, 15689, 14111, 19337, 31427, 175151, 175151, 175151, 175151, 175151
Offset: 1

Views

Author

Max Barrentine, Oct 02 2015

Keywords

Comments

The initial terms of the set of n coprime composite numbers that minimizes the difference between the first and last terms, and then minimizes the average of the terms.

Crossrefs

Subsequence of A002808.
First column of A261987.
Cf. A264482, A264483.
Showing 1-4 of 4 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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