A186394 Numbers k such that there are 2 primes between 100*k and 100*k + 99.

3020, 3709, 4484, 4617, 4806, 4921, 5072, 5423, 5616, 6041, 6194, 6231, 6452, 6485, 6683, 6828, 7101, 7365, 7454, 7532, 7839, 8096, 8157, 8728, 8738, 9221, 9486, 9635, 9796, 10152, 10506, 10720, 10852, 11261, 11621, 11736, 11953, 11992

Offset

1,1

Comments

There are 780 possible prime patterns for centuries having 2 primes. - Tim Johannes Ohrtmann, Aug 27 2015

Links

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

Example

3020 is in this sequence because there are 2 primes between 302000 and 302099 (302009 and 302053).

Prog

(Sage)
def is_A186394(n):
    np0 = next_prime(next_prime(100*n))
    np1 = next_prime(np0)
    return np0 <= 100*n+99 and np1 > 100*n+99  # D. S. McNeil, Feb 21 2011
(PARI) for(n=1, 1e6, if(sum(k=100*n, 100*(n+1), ispseudoprime(k))==2, print1(n", "))); \\ Charles R Greathouse IV, Feb 21 2011
(PARI) N=100; s=0; forprime(p=2, 4e9, if(p>N, if(s==2, print1((N\100)-1, ", ")); s=1; N=100*(p\100+1), s++)) \\ Charles R Greathouse IV, Feb 21 2011

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).

Sequence in context: A086746 A031816 A252381 * A236200 A252620 A104960

Adjacent sequences: A186391 A186392 A186393 * A186395 A186396 A186397

Keyword

nonn

Author

Tim Johannes Ohrtmann, Feb 20 2011

Status

approved