A075018 Smallest k such that the concatenation k, k-1,k-2,k-3 is divisible by n; or 0 if no such number exists.

3, 3, 3, 5, 3, 3, 5, 5, 6, 3, 18, 9, 11, 5, 3, 15, 13, 15, 19, 23, 18, 29, 29, 15, 28, 11, 33, 5, 4, 3, 40, 15, 18, 13, 18, 15, 28, 19, 24, 23, 26, 39, 7, 51, 33, 29, 55, 15, 53, 53, 30, 63, 54, 33, 18, 5, 57, 41, 56, 63, 69, 71, 60, 15, 63

Offset: 1

Author

Amarnath Murthy, Sep 01 2002

Keywords

• base
• nonn

Examples

			a(7) = 5 as 7 divides 5432.
		

Crossrefs

Cf. A075113, A075114, A075115, A075116, A075117.

Programs

Mathematica

Transpose[Flatten[Table[Select[Reverse[Partition[Range[100,0,-1], 4,1]], Divisible[FromDigits[ Flatten[IntegerDigits/@#]],n]&,1],{n,70}],1]] [[1]] (* Harvey P. Dale, Nov 22 2011 *)

Extensions

Corrected and extended by Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 19 2003