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%I #10 Sep 28 2018 10:30:35
%S 2,2,3,4,5,12,7,8,9,20,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,
%T 26,27,56,29,30,31,32,33,34,35,72,37,38,39,40,41,42,43,44,45,46,47,48,
%U 49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,132,67,68,69,70,71,72,73,74,75,76,77,156,79,80,81
%N a(n) = s(k)-s(j), where (s(k),s(j)) is the least pair of distinct triangular numbers for which n divides their difference.
%C For a guide to related sequences, see A204892.
%H Antti Karttunen, <a href="/A205006/b205006.txt">Table of n, a(n) for n = 1..23515</a>
%t (See the program at A205002.)
%o (PARI) A205006(n) = for(k=2,oo,my(sk=binomial(k+1,2)); for(j=1,k-1,if(!((sk-binomial(j+1,2))%n),return(sk-binomial(j+1,2))))); \\ _Antti Karttunen_, Sep 27 2018
%Y Cf. A000217, A205002, A205007, A204892.
%Y Cf. A318894 (gives the positions where a(n) is not n).
%K nonn
%O 1,1
%A _Clark Kimberling_, Jan 21 2012
%E More terms from _Antti Karttunen_, Sep 27 2018
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