A206001 Least k such that k*2^m + 1 has a covering set with precisely n primes.

271129, 78557, 1777613, 169073869

Offset: 6

Author

Arkadiusz Wesolowski, Feb 10 2012

Keywords

• more
• nonn

Comments

a(10) > 2^31. a(11) = 1143502909. - Arkadiusz Wesolowski, Apr 29 2012

Examples

			271129 has the covering set {3, 5, 7, 13, 17, 241}.
78557 has the covering set {3, 5, 7, 13, 19, 37, 73}.
1777613 has the covering set {3, 5, 7, 13, 17, 19, 109, 433}.
169073869 has the covering set {3, 5, 7, 11, 13, 41, 61, 151, 331}.
		

Links

• Wikipedia, Covering set
• Wikipedia, Sierpinski number

Crossrefs

Cf. A076336.