A034988 a(n) is root of smallest square starting with a string of n 'digit_6's.

8, 257, 2581, 2582, 258198, 2581988, 8164966, 25819889, 816496581, 8164965809, 258198889746, 2581988897471, 8164965809277, 25819888974716, 258198889747161, 816496580927726, 81649658092772603, 2581988897471611256, 8164965809277260327

Offset

1,1

Links

Table of n, a(n) for n=1..19.

Example

a(5) = 258198^2 = {66666}207204.

Mathematica

For[ i = 1, i < 20, i++, zeros = 0; isFound = False; While[ !isFound, low = Ceiling[ Sqrt[ 2/3*(10^i - 1)*10^zeros ] ]; high = Floor[ Sqrt[ (2/3*(10^i - 1) + 1)*10^zeros ] ]; isFound = (low <= high); zeros++ ]; Print[ low, " ", low^2 ] ]

Crossrefs

Cf. A034989.

Sequence in context: A103488 A341479 A041487 * A230271 A221778 A172127

Adjacent sequences: A034985 A034986 A034987 * A034989 A034990 A034991

Keyword

nonn,base

Author

Patrick De Geest, Nov 15 1998

Extensions

Program and more terms from Jonathan Cross (jcross(AT)wcox.com), Oct 15 2001

Status

approved