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

1,2

Links

Table of n, a(n) for n=1..12.

Example

a(3) = 32103 = 123 * 261.

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}]

Crossrefs

Cf. A078205.

Sequence in context: A269285 A133052 A365629 * A230466 A201248 A207553

Adjacent sequences: A078201 A078202 A078203 * A078205 A078206 A078207

Keyword

base,nonn

Author

Amarnath Murthy, Nov 22 2002

Extensions

More terms from Harvey P. Dale, Dec 07 2002

More terms from Sascha Kurz, Jan 04 2003

Status

approved