cp's OEIS Frontend

A247383 Smallest number m such that gcd(m,EKG(m)) = n, where EKG = A064413, the EKG sequence.

%I A247383 #7 Aug 01 2019 03:48:47
%S A247383 1,2,6,52,10,12,14,8,63,110,165,396,689,126,225,144,34,270,38,120,273,
%T A247383 1430,828,2088,1475,1014,432,476,58,4290,62,576,495,612,5180,2448,
%U A247383 4477,684,468,40,697,4158,3139,6028,810,8602,8601,4752,2499,850,867,5148
%N A247383 Smallest number m such that gcd(m,EKG(m)) = n, where EKG = A064413, the EKG sequence.
%C A247383 A247379(a(n)) = n and A247379(m) != n for m < a(n).
%H A247383 Reinhard Zumkeller, <a href="/A247383/b247383.txt">Table of n, a(n) for n = 1..206</a>
%o A247383 (Haskell)
%o A247383 import Data.IntMap (empty, member, (!), insert)
%o A247383 a247383 n = a247383_list !! (n-1)
%o A247383 a247383_list = f 1 1 empty where
%o A247383    f x z m | member x m = m ! x : f (x + 1) (x + 1) m
%o A247383            | member y m = f x (z + 1) m
%o A247383            | otherwise  = f x (z + 1) (insert y z m)
%o A247383            where y = a247379 z
%Y A247383 Cf. A064413, A247379.
%K A247383 nonn
%O A247383 1,2
%A A247383 _Reinhard Zumkeller_, Sep 16 2014