A162711 - OEIS

%I #8 Nov 11 2013 10:30:03

%S 1,2,23,3,34,345,4,45,456,4567,5,56,567,5678,56789,6,67,678,6789,

%T 67891,678910,7,78,789,7891,78910,789101,7891011,8,89,891,8910,89101,

%U 891011,8910111,89101112,9,91,910,9101,91011,910111,9101112,91011121,910111213

%N Triangle read by rows: T(n,k) = value of the string of length k beginning at position n in the concatenation of natural numbers in decimal representation, 1<=k<=n.

%C A055642(T(n,k)) <= k;

%C T(n,1)=A007376(n); T(n,k)=10*T(n,k-1)+A007376(k), 1<k<=n;

%C T(n,2)=A136414(n) for n>1.

%H Reinhard Zumkeller, <a href="/A162711/b162711.txt">Rows n = 1..125 of table, flattened</a>

%o (Haskell)

%o import Data.List (inits, tails)

%o a162711 n k = a162711_tabl !! (n-1) !! (k-1)

%o a162711_row n = a162711_tabl !! (n-1)

%o a162711_tabl = map (map (read . concatMap show) . tail . inits) $

%o                zipWith take [1..] $ tails a007376_list :: [[Integer]]

%o -- _Reinhard Zumkeller_, Nov 11 2013

%Y Cf. A224841 where n is the position of the last digit of the string.

%K base,nonn,tabl

%O 1,2

%A _Reinhard Zumkeller_, Jul 11 2009