Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #14 Sep 29 2018 18:41:14
%S 3,8,3,8,5,12,7,8,9,20,11,12,13,28,15,16,17,72,19,20,21,44,23,24,75,
%T 52,27,28,29,60,31,32,33,68,35,72,37,76,39,40,41,84,43,44,45,92,47,48,
%U 147,200,51,52,53,108,55,56,57,116,59,60,61,124,63,64,65,132,67,68,69,140,71,72,73,148,75,76,77,156,79,80,81,164
%N a(n) = k^2 - j^2, where (k^2,j^2) is the least pair of distinct squares for which n divides their difference.
%C For a guide to related sequences, see A204892.
%H Antti Karttunen, <a href="/A204998/b204998.txt">Table of n, a(n) for n = 1..23005</a>
%F a(n) = A204996(n) - A204997(n).
%t (See the program at A204994.)
%o (PARI) A204998(n) = { my(d); for(k=sqrtint(1+n), oo, for(j=1,k-1,if(!((d=(k^2)-(j^2))%n),return(d),if(d<n,break)))); }; \\ _Antti Karttunen_, Sep 28 2018
%Y Cf. A204994, A204892, A204996, A204997, A204999.
%K nonn
%O 1,1
%A _Clark Kimberling_, Jan 21 2012
%E More terms from _Antti Karttunen_, Sep 28 2018