A027662 a(n)/1000 gives sqrt(n) to 3 places after the decimal point.

1000, 1414, 1732, 2000, 2236, 2449, 2646, 2828, 3000, 3162, 3317, 3464, 3606, 3742, 3873, 4000, 4123, 4243, 4359, 4472, 4583, 4690, 4796, 4899, 5000, 5099, 5196, 5292, 5385, 5477, 5568, 5657, 5745, 5831, 5916, 6000, 6083, 6164, 6245, 6325, 6403, 6481, 6557, 6633

Offset

1,1

Links

Table of n, a(n) for n=1..44.

Maple

lprint(round(evalf(1000*sqrt(n))));

Mathematica

Table[Floor[1000*Sqrt[n]+1/2], {n, 40}]  (* Harvey P. Dale, Apr 22 2011 *)

Prog

(Python)
from math import isqrt
def A027662(n): return (m:=isqrt(k:=n*10**6))+int((k-m*(m+1)<<2)>=1) # Chai Wah Wu, Jul 30 2022

Crossrefs

Cf. A027661, A027663, A027664.

Sequence in context: A105276 A145517 A342975 * A004265 A004266 A004267

Adjacent sequences: A027659 A027660 A027661 * A027663 A027664 A027665

Keyword

nonn,base

Author

N. J. A. Sloane

Status

approved