A078265 Integer part of the geometric mean of all the distinct numbers formed by permuting the digits of concatenation of numbers from 1 to n.

1, 15, 207, 2544, 30091, 347096, 3931343, 43906441, 484912312, 5306957044

Offset

1,2

Comments

For n < 10 there are n! distinct numbers.

Links

Table of n, a(n) for n=1..10.

Example

a(3) = floor((123*132*213*231*312*321)^(1/6)) = floor(207.581...) = 207.
a(4) = floor((1234*1243*1324*1342*1423*1432*...*4312*4321)^(1/24)) = floor(2544.967...) = 2544.

Mathematica

a[n_] := Floor[ (Times @@ FromDigits /@ Permutations[Range[n]])^(1/n!) ]; Table[a[n], {n, 1, 10}] (* Ryan Propper, Jul 21 2006 *)

Crossrefs

Cf. A071268, A078266.

Sequence in context: A362809 A063906 A194481 * A089138 A271333 A051813

Adjacent sequences: A078262 A078263 A078264 * A078266 A078267 A078268

Keyword

base,more,nonn

Author

Amarnath Murthy, Nov 24 2002

Extensions

More terms from Ryan Propper, Jul 21 2006

Status

approved