A186404 Numbers k such that there are 12 primes between 100*k and 100*k + 99.

11, 15, 17, 18, 28, 30, 37, 45, 46, 47, 50, 56, 60, 67, 68, 76, 85, 91, 98, 101, 103, 106, 118, 122, 125, 126, 129, 131, 136, 137, 144, 145, 148, 151, 152, 153, 157, 160, 164, 169, 173, 199, 203, 207, 221, 226, 235, 236, 241

Offset: 1

Author

Tim Johannes Ohrtmann, Feb 20 2011

Keywords

• nonn

Comments

There are 27836859 possible prime patterns for centuries having 12 primes. - Tim Johannes Ohrtmann, Aug 27 2015

Examples

			11 is in this sequence because there are 12 primes between 1100 and 1199 (1103, 1109, 1117, 1123, 1129, 1151, 1153, 1163, 1171, 1181, 1187 and 1193).
		

Links

• T. D. Noe, Table of n, a(n) for n = 1..1000

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

Mathematica

Select[Range[250],PrimePi[100#+99]-PrimePi[100#]==12&] (* Harvey P. Dale, Sep 20 2011 *)

PARI

for(n=1, 1e6, if(sum(k=100*n, 100*(n+1), ispseudoprime(k))==12, print1(n", "))); \\ Charles R Greathouse IV, Feb 21 2011

PARI

N=100; s=0; forprime(p=2, 4e9, if(p>N, if(s==12, print1((N\100)-1, ", ")); s=1; N=100*(p\100+1), s++)) \\ Charles R Greathouse IV, Feb 21 2011