A092660 Number of consecutive prime runs of 9 primes congruent to 1 mod 4 below 10^n.

0, 0, 0, 0, 1, 6, 71, 851, 8919, 90049, 894724

Offset

1,6

Links

Table of n, a(n) for n=1..11.

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 3 mod 4.

Example

a(6)=6 because 6 sets of 9 primes occur below 10^6, each run interrupted by a prime congruent to 3 mod 4.

Crossrefs

Cf. A092661 A092662.

Cf. A162865. [From Rick L. Shepherd, Jul 15 2009]

Sequence in context: A099339 A213530 A023038 * A186658 A341967 A371366

Adjacent sequences: A092657 A092658 A092659 * A092661 A092662 A092663

Keyword

more,nonn

Author

Enoch Haga, Mar 02 2004

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

Status

approved