%I #11 Jul 13 2013 12:01:55
%S 3,17,37,50,52,54,56,57,58,60,62,64,66,68,77,97,117,137,157,177,201,
%T 231,261,281,284,287,290,291,293,296,299,302,305,308,321,351,381,411,
%U 441,471,501,531,561,581,584,587,590,591,593,596
%N Position of n-th 3 in A007376.
%C A007376(a(n)) = 3.
%H Reinhard Zumkeller, <a href="/A031290/b031290.txt">Table of n, a(n) for n = 1..10000</a>
%o (Haskell)
%o import Data.List (elemIndices)
%o a031290 n = a031290_list !! (n-1)
%o a031290_list = map (+ 1) $ elemIndices 3 a007376_list
%o -- _Reinhard Zumkeller_, Jul 28 2011
%Y Cf. A193428; A031287, A031288, A031289, A031291, A031292, A031293, A031294, A031295, A031296.
%K nonn,less,base
%O 1,1
%A _Clark Kimberling_