A078204 Smallest multiple of the concatenation of 1 up to n that begins with the concatenation of n down to 1.

1, 216, 32103, 4321468, 543217035, 65432173824, 7654321572835, 876543212074068, 98765432187654312, 109876543212580239340, 11109876543210457373921742, 12111098765432151566924849880

Offset: 1

Author

Amarnath Murthy, Nov 22 2002

Keywords

• base
• nonn

Examples

			a(3) = 32103 = 123 * 261.
		

Crossrefs

Cf. A078205.

Programs

Mathematica

f[n_] := Module[{upto = FromDigits[Range[n]], downfrom = FromDigits[Reverse[Range[n]]], i = 1}, While[upto - Mod[10^i downfrom, upto] > 10^i, i++ ]; 10^i downfrom + upto - Mod[10^i downfrom, upto]]; Table[f[n], {n, 2, 9}]

Extensions

More terms from Harvey P. Dale, Dec 07 2002

More terms from Sascha Kurz, Jan 04 2003