cp's OEIS Frontend

A265111 A rearrangement of the terms of A027746 (seen as flat list) such that adjacent terms are distinct.

%I A265111 #5 Dec 02 2015 16:23:55
%S A265111 1,2,3,2,5,2,3,2,7,2,3,2,5,3,2,11,2,3,2,13,2,7,2,5,3,2,17,2,3,2,19,3,
%T A265111 2,5,2,7,3,2,11,2,23,2,3,2,5,2,13,5,2,3,2,7,3,2,29,3,2,5,3,2,31,2,11,
%U A265111 3,2,17,2,7,5,2,3,2,37,3,2,19,2,13,3,2,5,2
%N A265111 A rearrangement of the terms of A027746 (seen as flat list) such that adjacent terms are distinct.
%H A265111 Reinhard Zumkeller, <a href="/A265111/b265111.txt">Table of n, a(n) for n = 1..10000</a>
%e A265111 .  k  | 1 2 3 4   5 6   7 8     9   10   11 12     13 14  15  16       17
%e A265111 .     | 1 2 3 2*2 5 2*3 7 2*2*2 3*3 2*5  11 2*2*3  13 2*7 3*5 2*2*2*2  17
%e A265111 . ----+-------------------------------------------------------------------
%e A265111 . a(n)| 1 2 3 2 5 2 3 2 7 2 3 2 5 3 2 11 2  3 2 13 2  7 2 5 3 2 17 2 3 2 ..
%o A265111 (Haskell)
%o A265111 a265111 n = a265111_list !! (n-1)
%o A265111 a265111_list = 1 : f 1 [] 0 1 where
%o A265111    f u [] w x = f 1 (reverse $ a027746_row' (u * x)) w (x + 1)
%o A265111    f u (v:vs) w x | v == w    = f (u * v) vs w x
%o A265111                   | otherwise = v : f u vs v x
%Y A265111 Cf. A027746, A265125 (partial products).
%K A265111 nonn
%O A265111 1,2
%A A265111 _Reinhard Zumkeller_, Dec 01 2015