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%I #14 Feb 25 2024 01:44:32
%S 1,1,2,1,3,1,1,2,4,1,1,3,1,2,1,1,2,2,2,1,3,1,1,2,2,3,1,3,1,2,1,1,2,1,
%T 1,2,1,3,1,1,2,2,2,1,4,1,2,1,1,2,1,1,2,4,1,1,2,2,2,1,1,3,1,2,1,1,2,1,
%U 1,2,1,3,1,1,2,2,2,1,1,3,3,1,1,2,1,1,3
%N First differences of indices of squarefree Pell numbers.
%H Amiram Eldar, <a href="/A107041/b107041.txt">Table of n, a(n) for n = 1..373</a>
%F a(n) = A107040(n+1)-A107040(n). - _R. J. Mathar_, Jan 04 2017
%t Rest[Differences[Flatten[Position[LinearRecurrence[{2,1},{1,2},100],_?SquareFreeQ]]]] (* _Harvey P. Dale_, May 30 2019 *)
%Y Cf. A000129, A005117, A107038, A107039, A107040.
%K nonn
%O 1,3
%A _Paul Barry_, May 09 2005
%E More terms from _Amiram Eldar_, Feb 25 2024