A205403 - OEIS

%I #11 Dec 06 2021 13:23:56

%S 1,2,1,2,1,4,2,1,2,2,1,3,6,2,1,3,2,2,1,7,3,8,2,1,4,3,5,2,1,4,9,3,5,2,

%T 1,4,6,3,9,2,1,10,4,6,3,15,2,1,2,4,10,3,3,2,1,7,15,4,20,3,8,2,1,11,7,

%U 4,5,3,6,2,1,5,11,7,4,14,3,6,2,1

%N a(n) is the index j < k such that n divides s(k)-s(j) for some j, where s(j) = floor((j+1)^2/2)/2, and k is the least index for which such a j exists.

%C For a guide to related sequences, see A204892.

%t (See the program at A205402.)

%Y Cf. A205402, A204892.

%K nonn

%O 1,2

%A _Clark Kimberling_, Jan 27 2012

%E Definition corrected by _Clark Kimberling_, Dec 05 2021