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 A115206 #11 Jun 28 2015 14:17:00
%S A115206 1,2,3,3,3,6,3,6,6,3,6,12,3,3,6,9,3,6,3,9,12,9,15,6,3,3,15,12,12,9,15,
%T A115206 6,9,6,3,18,15,3,6,9,21,15,15,21,6,30,15,24,3,6,15,6,3,3,6,21,3,6,27,
%U A115206 12,12,21,18,18,9,15,18,9,3,21,15,3,15,18,15,12,9,6,15,6,6,12,9,12,9,42,9
%N A115206 Least number d such that prime(n) -/+ 2d form a prime pair; prime(n) being the n-th prime.
%F A115206 a(n) = A078611(n)/2.
%t A115206 f[n_] := Block[{k = 1, p = Prime@n}, While[ !PrimeQ[p - 2k] || !PrimeQ[p + 2k], k++ ]; k]; Table[f[n], {n, 3, 90}] (* _Robert G. Wilson v_, Mar 14 2006 *)
%Y A115206 Cf. A078611.
%K A115206 nonn
%O A115206 3,2
%A A115206 _Lekraj Beedassy_, Mar 04 2006
%E A115206 Corrected by _N. J. A. Sloane_, Mar 05 2006
%E A115206 More terms from _Robert G. Wilson v_, Mar 14 2006