A034994 Square root of smallest square starting with a string of n 9's.

3, 315, 3161, 31622, 316227, 3162277, 31622776, 316227765, 316227766, 31622776601, 316227766016, 3162277660167, 31622776601683, 316227766016837, 3162277660168378, 31622776601683792

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..998

Example

a(5) = 316227^2 = {99999}515529.

Maple

f:= proc(n) local d, q, x;
  for d from n do
     q:= 10^d-10^(d-n);
     x:= isqrt(q);
     if x^2 < q then x:= x+1 fi;
     if x^2 < 10^d then return x fi
  od
end proc:
map(f, [$1..20]); # Robert Israel, Sep 28 2018

Crossrefs

Cf. A034995.

Sequence in context: A039954 A134215 A361032 * A139541 A168440 A067667

Adjacent sequences: A034991 A034992 A034993 * A034995 A034996 A034997

Keyword

nonn,base

Author

Patrick De Geest, Nov 15 1998

Extensions

More terms from Hans Havermann, Jun 18 2001

Status

approved