A077513 Smallest n-digit squarefree number beginning with n.

1, 21, 301, 4001, 50001, 600001, 7000001, 80000002, 900000001, 1000000001, 11000000001, 120000000001, 1300000000001, 14000000000001, 150000000000001, 1600000000000001, 17000000000000002, 180000000000000001

Offset

1,2

Links

Table of n, a(n) for n=1..18.

Mathematica

snsf[n_]:=Module[{k=0, p=n*10^(n-IntegerLength[n])}, While[!SquareFreeQ[ p+k], k++]; p+k]; Array[snsf, 20] (* Harvey P. Dale, Apr 08 2018 *)

Crossrefs

Cf. A077514.

Sequence in context: A007592 A019664 A019839 * A079517 A021784 A019618

Adjacent sequences: A077510 A077511 A077512 * A077514 A077515 A077516

Keyword

base,nonn

Author

Amarnath Murthy, Nov 08 2002

Extensions

More terms from Sascha Kurz, Jan 04 2003

Status

approved