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%I #5 Apr 09 2015 16:28:24
%S 2,4,3,5,2,7,2,8,3,7,4,6,4,10,8,4,12,2,11,3,10,6,11,4,8,6,12,10,4,12,
%T 4,12,8,7,4,14,2,19,5,21,3,17,7,9,7,13,4,19,7,13,5,17,5,21,9,11,5,17,
%U 3,17,7,9,13,17,5,17,6,12,5,24,4,16,12,8,6,15,2
%N Index of A166133(n) in the list of divisors of A166133(n-1)^2 - 1.
%C A166133(n) = A027750(A166133(n-1)^2-1,a(n)).
%H Reinhard Zumkeller, <a href="/A256751/b256751.txt">Table of n, a(n) for n = 4..10000</a>
%e n = 12: A166133(12) = 9, A166133(12-1) = 10, 10^2 - 1 = 99,
%e 9 is the third term of divisors(99) = [1,3,9,11,33,99],
%e therefore a(12) = 3;
%e n = 13: A166133(13) = 16, A166133(13-1) = 9, 9^2 - 1 = 80,
%e 16 is the seventh term of divisors(80) = [1,2,4,5,8,10,16,20,40,80],
%e therefore a(13) = 7.
%o (Haskell)
%o import Data.List (elemIndex); import Data.Maybe (fromJust)
%o a256751 n = (+ 1) $ fromJust $
%o a166133 n `elemIndex` a027750_row' (a166133 (n - 1) ^ 2 - 1)
%Y Cf. A166133, A027750.
%K nonn
%O 4,1
%A _Reinhard Zumkeller_, Apr 09 2015
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