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 A204897 #9 Oct 09 2018 15:15:48 %S A204897 1,1,1,1,1,1,2,1,1,1,1,1,2,1,1,1,1,1,2,1,1,1,2,1,2,1,1,1,1,1,2,1,2,1, %T A204897 1,1,2,1,1,1,1,1,2,1,1,1,2,1,2,1,1,1,2,1,2,1,1,1,1,1,2,1,2,1,1,1,2,1, %U A204897 1,1,1,1,2,1,2,1,1,1,2,1,1,1,2,1,2,1,1,1,2,1,2,1,2,1,1,1,2,1,1,1,1,1,2,1,1 %N A204897 a(n) = (p(n)-q(n))/n, where (p(n), q(n)) is the least pair of primes for which n divides p(n)-q(n). %C A204897 For a guide to related sequences, see A204892. %C A204897 It seems that a(A007921(n)) = 2 for all n. - _Antti Karttunen_, Oct 09 2018 %H A204897 Antti Karttunen, <a href="/A204897/b204897.txt">Table of n, a(n) for n = 1..12000</a> %e A204897 (3-2)/1=1 %e A204897 (5-3)/2=1 %e A204897 (5-2)/3=1 %e A204897 (7-3)/4=1 %e A204897 (7-2)/5=1 %e A204897 (11-5)/6=1 %e A204897 (17-3)/7=2 %t A204897 (See the program at A204892.) %o A204897 (PARI) A204897(n) = { my(d); forprime(p=3,oo, forprime(q=2,p-1,if(!((d=(p-q))%n),return(d/n),if(d<n,break)))); }; \\ _Antti Karttunen_, Oct 09 2018 %Y A204897 Cf. A007921, A204892, A204896, A000040. %K A204897 nonn %O A204897 1,7 %A A204897 _Clark Kimberling_, Jan 20 2012 %E A204897 More terms from _Antti Karttunen_, Oct 09 2018