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 A080370 #6 Mar 29 2015 11:55:39
%S A080370 0,1,3,5,8,10,13,15,18,22,24,28,31,33,36,40,44,46,50,53,55,59,62,66,
%T A080370 70,74,76,79,81,84,90,95,99,101,106,109,113,117,120,124,128,130,135,
%U A080370 138,141,143,149,155,159,161,165,169,171,176,180,184,188,191,195,198,200
%N A080370 Number of distinct values among the differences prime(j)-prime(i), 1 <= i < j <= n.
%e A080370 n=1: no differences arise; n=3: primes={2, 3, 5}, C[3, 2]=3, differences={3, 2, 1}, a(3)=3;
%e A080370 n=7: primes={2, 3, 5, 7, 11, 13, 17}, differences={15, 14, 12, 10, 6, 4, 11, 10, 8, 6, 2, 9, 8, 6, 4, 5, 4, 2, 3, 2, 1}, distinct terms ={15, 14, 12, 11, 10, 9, 8, 6, 5, 4, 3, 2, 1}, a(7)=13.
%t A080370 f[n_] := Length[ Union[ Flatten[ Table[ Prime[i] - Prime[j], {i, 2, n}, {j, i - 1}]] ]]; Table[ f[n], {n, 61}] (* _Robert G. Wilson v_, Jul 30 2004 *)
%K A080370 nonn
%O A080370 1,3
%A A080370 _Labos Elemer_, Feb 26 2003