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 A090807 #21 Aug 27 2025 11:10:07 %S A090807 3,5,1997,2237,6824897,1356705137,3637803390827 %N A090807 First prime in the earliest chain of n consecutive primes with gaps 2^1, 2^2, ..., 2^(n-1). %H A090807 <a href="/index/Pri#gaps">Index entries for primes, gaps between</a>. %e A090807 The earliest chain of 4 consecutive primes separated by gaps 2^1, 2^2, 2^3 is: 1997, 1999, 2003, 2011. Hence a(4) = 1997. %Y A090807 Cf. A000230. %Y A090807 Essentially the same as A079014. %K A090807 nonn,hard,more,changed %O A090807 2,1 %A A090807 _Joseph L. Pe_, Feb 12 2004 %E A090807 a(7)-a(8) from _Donovan Johnson_, Mar 23 2013