A077309 Concatenation of n numbers starting with n.

1, 23, 345, 4567, 56789, 67891011, 78910111213, 89101112131415, 91011121314151617, 10111213141516171819, 1112131415161718192021, 121314151617181920212223

Offset: 1

Author

Amarnath Murthy, Nov 03 2002

Keywords

• base
• easy
• nonn

Links

• Michael De Vlieger, Table of n, a(n) for n = 1..333

Programs

Mathematica

Table[FromDigits@ Flatten@ Take[#, {n, n + (n - 1)}], {n, Ceiling[Length[#]/2]}] &@ Array[IntegerDigits, 23] (* Michael De Vlieger, May 13 2017 *)

Extensions

a(7) corrected by Michael De Vlieger, May 13 2017