A126981 - OEIS

A126981

Largest perfect square less than 2*10^n.

1, 16, 196, 1936, 19881, 199809, 1999396, 19998784, 199996164, 1999967841, 19999899241, 199999467369, 1999998409369, 19999991458225, 199999982358225, 1999999950806881, 19999999932878736, 199999999552824025

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Table of n, a(n) for n=0..17.

FORMULA

a(n) = floor(sqrt(2*10^n))^2.

EXAMPLE

a(4) = 19881 because 19881 is the largest perfect square less than 2*10^4.

MATHEMATICA

Table[Floor[Sqrt[2*10^k]]^2, {k, 0, 30}]

CROSSREFS

Sequence in context: A017318 A173668 A373108 * A086940 A016173 A005747

Adjacent sequences: A126978 A126979 A126980 * A126982 A126983 A126984

KEYWORD

easy,nonn

AUTHOR

Adam M. Kalman (akalman(AT)icsd.k12.ny.us), Mar 21 2007

STATUS

approved