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A258703 a(n) = floor(n/sqrt(2) - 1/2). 1
-1, 0, 0, 1, 2, 3, 3, 4, 5, 5, 6, 7, 7, 8, 9, 10, 10, 11, 12, 12, 13, 14, 15, 15, 16, 17, 17, 18, 19, 20, 20, 21, 22, 22, 23, 24, 24, 25, 26, 27, 27, 28, 29, 29, 30, 31, 32, 32, 33, 34, 34, 35, 36, 36, 37, 38, 39, 39, 40, 41, 41, 42, 43, 44, 44, 45, 46, 46, 47, 48, 48, 49, 50, 51, 51, 52, 53, 53 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

Equals floor(1/(exp(sqrt(2)/n)-1)) for all nonzero integers n [O'Bryant].

a(n) = floor(n*sqrt(2) - 1) / 2). - Reinhard Zumkeller, Jun 09 2015

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

K. O'Bryant, The sequence of fractional parts of roots, arXiv preprint, arXiv:1410.2927 [math.NT], 2014

MATHEMATICA

Table[Floor[n/Sqrt[2] - 1/2], {n, 0, 100}] (* Vincenzo Librandi, Jun 09 2015 *)

PROG

(MAGMA) [Floor(n/Sqrt(2) - 1/2): n in [0..80]]; // Vincenzo Librandi, Jun 09 2015

(Haskell)

a258703 = floor . (/ 2) . subtract 1 . (* sqrt 2) . fromIntegral

-- Reinhard Zumkeller, Jun 09 2015

(PARI) vector(100, n, n--; floor(n/sqrt(2) - 1/2)) \\ G. C. Greubel, Sep 30 2018

CROSSREFS

Cf. A078608, A129935.

Cf. A049472, A001951.

Sequence in context: A175406 A210435 A181534 * A067022 A113818 A136746

Adjacent sequences:  A258700 A258701 A258702 * A258704 A258705 A258706

KEYWORD

sign

AUTHOR

N. J. A. Sloane, Jun 09 2015

STATUS

approved

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Last modified June 25 04:25 EDT 2019. Contains 324346 sequences. (Running on oeis4.)