This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A186401 #30 Mar 22 2024 03:44:07 %S A186401 41,43,70,73,83,89,99,115,117,120,123,128,132,138,143,150,158,161,163, %T A186401 168,171,172,193,200,202,208,209,216,222,223,225,229,233,237,239,246, %U A186401 276,278,282,288,290,294,300,302,303,304 %N A186401 Numbers k such that there are 9 primes between 100*k and 100*k + 99. %C A186401 There are 11555200 possible prime patterns for centuries having 9 primes. - _Tim Johannes Ohrtmann_, Aug 27 2015 %H A186401 T. D. Noe, <a href="/A186401/b186401.txt">Table of n, a(n) for n = 1..1000</a> %e A186401 41 is in this sequence because there are 9 primes between 4100 and 4199 (4111, 4127, 4129, 4133, 4139, 4153, 4157, 4159 and 4177). %t A186401 Select[Range[350],PrimePi[100#+99]-PrimePi[100#]==9&] (* _Harvey P. Dale_, Sep 05 2023 *) %o A186401 (PARI) for(n=1, 1e6, if(sum(k=100*n, 100*(n+1), ispseudoprime(k))==9, print1(n", "))); \\ _Charles R Greathouse IV_, Feb 21 2011 %o A186401 (PARI) N=100; s=0; forprime(p=2, 1e6, if(p>N, if(s==9, print1((N\100)-1, ", ")); s=1; N=100*(p\100+1), s++)) \\ _Charles R Greathouse IV_, Feb 21 2011 %Y A186401 Cf. A038822 (number of primes between 100n and 100n+99), A186311 (first occurrences). %Y A186401 Cf. A181098 (no primes), A186393-A186408 (1 to 16 primes), A186509 (17 primes), A361723 (18 primes). %K A186401 nonn %O A186401 1,1 %A A186401 _Tim Johannes Ohrtmann_, Feb 20 2011