A068124 Smallest number whose n-th power begins with n n's; n-th root of A068123.

1, 15, 322, 1452, 88909, 2955639, 25880899, 415533397, 215443469, 25144122307797731891, 1891851504074453542774, 389309950637308214633931, 71656315545775490294342978, 8696027755149851609001142655

Offset

1,2

Comments

a(n) = A068123(n)^(1/n).

Links

Ray Chandler, Table of n, a(n) for n = 1..22

Example

a(3) = 322 as 322^3 = 33386248 begins with 333.

Mathematica

a[n_] := Block[{t = Flatten@Table[IntegerDigits@n, {n}], m, v, h=0}, m = Length@t; z = FromDigits@t; While[ Take[ IntegerDigits[(v = Ceiling[(z 10^h) ^ (1/n)])^n], m] != t, h++]; v]; Array[a, 30] (* Giovanni Resta, Jul 12 2016 *)

Crossrefs

Cf. A068123.

Sequence in context: A132392 A131699 A077738 * A094399 A219253 A119296

Adjacent sequences: A068121 A068122 A068123 * A068125 A068126 A068127

Keyword

base,easy,nonn

Author

Amarnath Murthy, Feb 21 2002

Extensions

Corrected and extended by David Wasserman, Dec 23 2002

More terms from Sascha Kurz, Feb 09 2003

Entry revised by N. J. A. Sloane, Aug 14 2006

Status

approved