A186397 - OEIS

%I #30 Mar 22 2024 03:45:55

%S 188,273,377,403,438,506,598,605,732,758,790,800,866,885,916,936,972,

%T 981,1031,1032,1060,1074,1075,1086,1103,1128,1136,1193,1194,1204,1218,

%U 1240,1248,1265,1280,1287,1293,1298,1390,1400

%N Numbers k such that there are 5 primes between 100*k and 100*k + 99.

%C There are 225044 possible prime patterns for centuries having 5 primes. - _Tim Johannes Ohrtmann_, Aug 27 2015

%H T. D. Noe, <a href="/A186397/b186397.txt">Table of n, a(n) for n = 1..1000</a>

%e 188 is in this sequence because there are 5 primes between 18800 and 18899 (18803, 18839, 18859, 18869 and 18899).

%o (PARI) for(n=1, 1e6, if(sum(k=100*n, 100*(n+1), ispseudoprime(k))==5, print1(n", "))); \\ _Charles R Greathouse IV_, Feb 21 2011

%o (PARI) N=100; s=0; forprime(p=2, 1e6, if(p>N, if(s==5, print1((N\100)-1, ", ")); s=1; N=100*(p\100+1), s++)) \\ _Charles R Greathouse IV_, Feb 21 2011

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

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

%K nonn

%O 1,1

%A _Tim Johannes Ohrtmann_, Feb 20 2011