A011548 Decimal expansion of sqrt(2) rounded to n places.

1, 14, 141, 1414, 14142, 141421, 1414214, 14142136, 141421356, 1414213562, 14142135624, 141421356237, 1414213562373, 14142135623731, 141421356237310, 1414213562373095, 14142135623730950, 141421356237309505, 1414213562373095049, 14142135623730950488

Offset

0,2

References

W. Rudin, Principles of Mathematical Analysis, 3rd ed., McGraw-Hill, 1976.

Links

G. C. Greubel, Table of n, a(n) for n = 0..995 (terms 0..200 from Vincenzo Librandi)

Mathematica

Round[Table[N[Sqrt[2], k] 10^(k - 1), {k, 20}]] (* Vincenzo Librandi, Aug 17 2013 *)
Module[{nn=20, s}, s=RealDigits[Sqrt[2], 10, nn+1][[1]]; Table[Round[ FromDigits[ Take[ s, n+1]]/10], {n, nn}]] (* Harvey P. Dale, Apr 04 2019 *)

Prog

(Python)
from math import isqrt
def A011548(n): return (m:=isqrt(k:=10**(n<<1)<<1))+int((k-m*(m+1)<<2)>=1) # Chai Wah Wu, Jul 29 2022

Crossrefs

Cf. A011547.

Sequence in context: A306558 A131583 A011547 * A039916 A378625 A241217

Adjacent sequences: A011545 A011546 A011547 * A011549 A011550 A011551

Keyword

nonn,base,easy

Author

N. J. A. Sloane

Status

approved