%I #11 Jul 13 2013 12:01:55
%S 4,19,39,59,70,72,74,76,78,79,80,82,84,86,88,99,119,139,159,179,204,
%T 234,264,294,311,314,317,320,323,324,326,329,332,335,338,354,384,414,
%U 444,474,504,534,564,594,611,614,617,620,623,624
%N Position of n-th 4 in A007376.
%C A007376(a(n)) = 4.
%H Reinhard Zumkeller, <a href="/A031291/b031291.txt">Table of n, a(n) for n = 1..10000</a>
%o (Haskell)
%o import Data.List (elemIndices)
%o a031291 n = a031291_list !! (n-1)
%o a031291_list = map (+ 1) $ elemIndices 4 a007376_list
%o -- _Reinhard Zumkeller_, Jul 28 2011
%Y Cf. A193428; A031287, A031288, A031289, A031290, A031292, A031293, A031294, A031295, A031296.
%K nonn,less,base
%O 1,1
%A _Clark Kimberling_