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A286567 Smallest prime factor of the n-th Jacobsthal number: a(n) = A020639(A001045(n)), with a(1)=a(2)=1. 4

%I #13 Sep 23 2018 16:39:02

%S 1,1,3,5,11,3,43,5,3,11,683,3,2731,43,3,5,43691,3,174763,5,3,23,

%T 2796203,3,11,2731,3,5,59,3,715827883,5,3,43691,11,3,1777,174763,3,5,

%U 83,3,2932031007403,5,3,47,283,3,43,11,3,5,107,3,11,5,3,59,2833,3,768614336404564651,715827883,3,5,11,3,7327657,5,3,11,56409643,3,1753,223,3,5,43,3

%N Smallest prime factor of the n-th Jacobsthal number: a(n) = A020639(A001045(n)), with a(1)=a(2)=1.

%H Hans Havermann, <a href="/A286567/b286567.txt">Table of n, a(n) for n = 1..1122</a>

%F a(n) = A020639(A001045(n)).

%t Rest[FactorInteger[#][[1,1]]&/@LinearRecurrence[{1,2},{0,1},100]] (* _Harvey P. Dale_, Sep 23 2018 *)

%o (Scheme) (define (A286567 n) (A020639 (A001045 n)))

%Y Cf. A001045, A020639, A278165.

%K nonn

%O 1,3

%A _Antti Karttunen_ & _Hans Havermann_, May 21 2017

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Last modified August 11 12:43 EDT 2024. Contains 375069 sequences. (Running on oeis4.)