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 A096521 #9 Aug 30 2019 15:18:41
%S A096521 25,9,1,2,20,18,127,844,573
%N A096521 Smallest exponent of 2 when the number of primes in the neighborhood of center=2^n and radius=ceiling(log(2^n)) equals n.
%e A096521 First in the suitable neighborhood of 2^25 no primes occur: a[0]=25, while corresponding around 2^127 6 primes arise: a[6]=127.
%t A096521 t=Table[Count[Table[PrimeQ[2^n+i], {i, -Ceiling[Log[2^n]//N], Ceiling[Log[2^n]//N]}], True], {n, 1, 256}] Table[Min[Flatten[Position[t, j]]], {j, 0, 10}]
%Y A096521 Cf. A096509-A096523.
%K A096521 nonn,more
%O A096521 0,1
%A A096521 _Labos Elemer_, Jul 12 2004