A092661 Number of consecutive prime runs of 9 primes congruent to 3 mod 4 below 10^n.

0, 0, 0, 0, 1, 8, 77, 897, 8949, 90276, 894951

Offset: 1

Author

Enoch Haga, Mar 02 2004

Keywords

• more
• nonn

Examples

			a(7)=77 because 77 sets of 9 primes occur below 10^7, each run interrupted by a prime congruent to 1 mod 4.
		

Crossrefs

Cf. A092660 A092662.

Cf. A162866. [From Rick L. Shepherd, Jul 15 2009]

Formula

Generate the prime sequence with primes labeled 1 mod 4 or 3 mod 4. Add count of primes to sequence if just 9 primes occur before interruption by a prime congruent to 1 mod 4

Extensions

a(9) from Rick L. Shepherd, Jul 15 2009

a(10) from Sean A. Irvine, Oct 25 2011

a(11) from Chai Wah Wu, Mar 18 2018