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%I #7 May 02 2015 10:26:46
%S 4,17,72,329,473,1906,9067,40680,124068,340694,579517,2967748,9677489,
%T 36774905,85005719,350057197,673138588,3731385891,9039525037,
%U 40395250381,121209164997,412091649984,1293483111622,3934831116232
%N Smallest number obtained by placing a + in the first n digits of decimal expansion of Pi.
%H Reinhard Zumkeller, <a href="/A085732/b085732.txt">Table of n, a(n) for n = 2..1000</a>
%H Dave Andersen, <a href="http://www.angio.net/pi/piquery">The Pi-Search Page</a>.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Pi.html">Pi</a>.
%e n=5: insert '+' in '31415':
%e a(5) = Min{3+1415=1418, 31+415=446, 314+15=329, 3141+5=3146} = 329.
%o (Haskell)
%o import Data.List (inits, tails); import Data.Function (on)
%o a085732 n = a085732_list !! (n-2)
%o a085732_list = map f $ drop 2 $ inits $ concatMap show a000796_list
%o where f xs = minimum $ init $ tail $
%o zipWith (on (+) read) (inits xs) (tails xs)
%o -- _Reinhard Zumkeller_, May 02 2015
%Y Cf. A000796.
%K nonn,base
%O 2,1
%A _Reinhard Zumkeller_, Jul 20 2003