cp's OEIS Frontend

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.

A181098 Primefree centuries (i.e., numbers k such that no prime exists between 100*k and 100*k+99).

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%I A181098 #24 Mar 22 2024 03:46:32
%S A181098 16718,26378,31173,39336,46406,46524,51782,55187,58374,58452,60129,
%T A181098 60850,63338,63762,67898,69587,71299,75652,78035,78269,80277,83674,
%U A181098 84213,89052,95490,97080,100881,101527,103438,105916,111772,112967
%N A181098 Primefree centuries (i.e., numbers k such that no prime exists between 100*k and 100*k+99).
%C A181098 The first consecutive terms are 473267, 473268; see A190639. - _M. F. Hasler_, May 15 2011
%H A181098 T. D. Noe, <a href="/A181098/b181098.txt">Table of n, a(n) for n = 1..1000</a>
%F A181098 a(n) = n + 100n/log n - O(n/log^2 n). - _Charles R Greathouse IV_, Sep 08 2017
%e A181098 16718 is a term because there is no prime between 1671800 and 1671899.
%t A181098 Flatten[Position[Differences[PrimePi[100*Range[0,113000]]],0]]-1 (* _Harvey P. Dale_, Dec 18 2021 *)
%o A181098 (PARI) is(n)=nextprime(100*n)>100*n+99 \\ _Charles R Greathouse IV_, Apr 28 2015
%Y A181098 Cf. A038822 (number of primes between 100n and 100n+99), A186311 (first occurrences).
%Y A181098 Cf. A186393-A186408 (1 to 16 primes), A186509 (17 primes), A361723 (18 primes).
%K A181098 nonn
%O A181098 1,1
%A A181098 _Jeff Burch_, Oct 02 2010