A186407 Numbers k such that there are 15 primes between 100*k and 100*k + 99.

8, 12, 16, 22, 23, 26, 33, 40, 49, 63, 75, 94, 375, 424, 1131, 1572, 3442, 3922, 7393, 9780, 13939, 16528, 17492, 29673, 71338, 75877, 237421, 464977, 514483, 687352, 747574, 981953, 1040840, 1269778, 1298137, 1346413, 1790287, 1884223, 2330647, 2527249, 2601874, 2813749

Offset: 1

Author

Tim Johannes Ohrtmann, Feb 20 2011

Keywords

• nonn

Comments

There are 12815608 possible prime patterns for centuries having 15 primes. - Tim Johannes Ohrtmann, Aug 27 2015

Examples

			8 is in this sequence because there are 15 primes between 800 and 899 (809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883 and 887).
		

Links

• Brian Kehrig, Table of n, a(n) for n = 1..1000 (terms 1..200 from T. D. Noe)

Crossrefs

Cf. A038822 (number of primes between 100n and 100n+99), A186311 (first occurrences).

Cf. A181098 (no primes), A186393-A186408 (1 to 16 primes), A186509 (17 primes), A361723 (18 primes).

Programs

PARI

for(n=1, 1e6, if(sum(k=100*n,100*(n+1), ispseudoprime(k))==15, print1(n", "))); \\ Charles R Greathouse IV, Feb 21 2011

PARI

N=100; s=0; forprime(p=2, 4e9, if(p>N, if(s==15, print1((N\100)-1,", ")); s=1; N=100*(p\100+1),s++)) \\ Charles R Greathouse IV, Feb 21 2011

Extensions

a(19)-a(42) from Charles R Greathouse IV, Feb 21 2011