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 A049298 #5 Oct 15 2013 22:30:27 %S A049298 0,0,2,2,2,4,2,2,2,4,2,4,2,4,3,2,2,4,2,4,3,4,2,4,2,4,2,4,2,6,2,2,3,4, %T A049298 3,4,2,4,3,4,2,6,2,4,3,4,2,4,2,4,3,4,2,4,3,4,3,4,2,6,2,4,3,2,3,6,2,4, %U A049298 3,6,2,4,2,4,3,4,3,6,2,4,2,4,2,6,3,4,3,4,2,6,3,4,3,4,3,4,2,4,3,4,2,6,2,4,5 %N A049298 Take reduced residue systems of n, generate its first differences, dRRS(n); sequence gives maximal value of dRSSS(n). %C A049298 Greatest values occur at primorial numbers (A002110). %e A049298 If n is prime, its reduced residue system consists of all numbers below n. But the difference 2 arises from d=1-(n-1)=-n+2 (mod n). %Y A049298 Cf. A048670. Essentially same as A048669. %K A049298 nonn %O A049298 1,3 %A A049298 _Labos Elemer_