A345685 a(n) is the smallest cardinality of all covering sets associated with Riesel number A101036(n).

6, 6, 7, 7, 6, 7, 6, 6, 6, 6, 7, 6, 6, 7, 7, 6

Offset

1,1

Comments

The condition for choosing a covering set is necessary as there are Riesel numbers with more than one covering set, see A263392.

Links

Table of n, a(n) for n=1..16.

Prime Wiki, Category:Riesel k=Riesel [Links to pages giving the covering sets of Riesel numbers]

Wikipedia, Riesel number

Example

   n | Riesel number | Covering set               | a(n)
--------------------------------------------------------
   1 |  509203       | {3, 5, 7, 13, 17, 241}     | 6
   2 |  762701       | {3, 5, 7, 13, 17, 241}     | 6
   3 |  777149       | {3, 5, 7, 13, 19, 37, 73}  | 7
   4 |  790841       | {3, 5, 7, 13, 19, 37, 73}  | 7
   5 |  992077       | {3, 5, 7, 13, 17, 241}     | 6
   6 | 1106681       | {3, 5, 7, 13, 19, 37, 73}  | 7
   7 | 1247173       | {3, 5, 7, 13, 17, 241}     | 6
   8 | 1254341       | {3, 5, 7, 13, 17, 241}     | 6
   9 | 1330207       | {3, 5, 7, 13, 17, 241}     | 6
  10 | 1330319       | {3, 5, 7, 13, 17, 241}     | 6
  11 | 1715053       | {3, 5, 7, 13, 19, 37, 73}  | 7
  12 | 1730653       | {3, 5, 7, 13, 17, 241}     | 6
  13 | 1730681       | {3, 5, 7, 13, 17, 241}     | 6
  14 | 1744117       | {3, 5, 7, 13, 19, 73, 109} | 7
  15 | 1830187       | {3, 5, 7, 13, 37, 73, 109} | 7
  16 | 1976473       | {3, 5, 7, 13, 17, 241}     | 6

Crossrefs

Cf. A101036, A244070, A244071, A244072, A244073, A244074, A263392.

Sequence in context: A190145 A351214 A195103 * A152485 A256684 A049005

Adjacent sequences: A345682 A345683 A345684 * A345686 A345687 A345688

Keyword

nonn,hard,more

Author

Felix Fröhlich, Jun 23 2021

Status

approved