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Position of first occurrence of n in A256918.
5

%I #25 May 03 2015 13:47:21

%S 1,4,3,5,7,11,29,13,10,15,122,19,200,31,24,18,299,22,824,16,33,124,

%T 945,41,26,202,21,37,3093,45,7059,40,126,301,53,66,13527,826,204,42,

%U 28658,36,40810,130,57,947,46657,64,80,44,303,208,57449,49,133,38,828

%N Position of first occurrence of n in A256918.

%C A256918(a(n)) = n and A256918(m) != n for m < a(n);

%C GCD(A257218(a(n)),A257218(a(n)+1)) = n;

%C if A257218 is a permutation, then also this sequence is a permutation;

%C a(n) < A257475(n); a(n) = A257475(n) - A257478(n).

%C a(n) >= A257122(n)-1. - _Ivan Neretin_, May 02 2015

%H Hiroaki Yamanouchi, <a href="/A257120/b257120.txt">Table of n, a(n) for n = 1..72</a>

%e See A257478.

%o (Haskell)

%o import Data.List (elemIndex); import Data.Maybe (fromJust)

%o a257120 = (+ 1) . fromJust . (`elemIndex` a256918_list)

%Y Cf. A256918, A257475, A257478, A257218.

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Apr 25 2015

%E a(41)-a(57) from _Hiroaki Yamanouchi_, May 03 2015