A048377 Append d digits d after each digit d in decimal expansion of n.

0, 11, 222, 3333, 44444, 555555, 6666666, 77777777, 888888888, 9999999999, 110, 1111, 11222, 113333, 1144444, 11555555, 116666666, 1177777777, 11888888888, 119999999999, 2220, 22211, 222222, 2223333, 22244444, 222555555, 2226666666

Offset

0,2

Comments

a(10^n) = 11 * 10^n; A007953(a(n)) = A003132(n) + A007953(n). [Reinhard Zumkeller, Jul 10 2011]

Links

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

Example

12 becomes 1 1 2 22 = 11222.

Mathematica

den[n_]:=Module[{idn=IntegerDigits[n]}, FromDigits[Flatten[Table[ Table[ idn[[i]], {idn[[i]]+1}], {i, Length[idn]}]]]]; Array[den, 30, 0] (* Harvey P. Dale, Sep 04 2013 *)

Prog

(Haskell)
import Data.Char (digitToInt)
a048377 :: Integer -> Integer
a048377 n =
   read $ concat $ zipWith replicate (map ((+ 1) . digitToInt) ns) ns
      where ns = show n
-- Reinhard Zumkeller, Jul 10 2011

Crossrefs

Cf. A048376.

Sequence in context: A341491 A064093 A087402 * A192686 A323416 A308438

Adjacent sequences: A048374 A048375 A048376 * A048378 A048379 A048380

Keyword

nonn,easy,base,nice,look

Author

Patrick De Geest, Mar 15 1999

Status

approved