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 A084294 #15 Aug 28 2019 08:16:24
%S A084294 2,2,2,2,2,3,3,2,3,3,3,4,4,3,4,4,5,5,5,5,4,5,5,7,6,6,5,5,5,5,7,7,7,7,
%T A084294 8,7,8,9,8,8,7,7,9,8,9,8,9,11,10,10,11,10,10,9,10,11,10,9,9,9,8,10,11,
%U A084294 11,10,11,12,12,12,12,12,12,13,13,13,13,14,14,14,14,15,15,15,14,15,14,13
%N A084294 Number of primes in the interval [prime(n),n+prime(n)].
%F A084294 a(n) = Pi(n+prime(n)) - n + 1 = A000720(n+A000040(n)) - n + 1. [corrected by _Michel Marcus_, Aug 28 2019]
%t A084294 t[x_] := Table[w, {w, Prime[x], x+Prime[x]}] Table[Count[PrimeQ[t[n]], True], {n, 1, 128}] (* or *) Table[PrimePi[n+Prime[n]]-n+1, {n, 1, 25}];
%o A084294 (PARI) a(n) = primepi(n+prime(n)) - n + 1; \\ _Michel Marcus_, Aug 28 2019
%Y A084294 Cf. A000040, A000720, A061067, A061068, A084295.
%K A084294 nonn
%O A084294 1,1
%A A084294 _Labos Elemer_, May 27 2003