

A001952


A Beatty sequence: a(n) = floor(n*(2 + sqrt(2))).
(Formerly M2534 N1001)


43



3, 6, 10, 13, 17, 20, 23, 27, 30, 34, 37, 40, 44, 47, 51, 54, 58, 61, 64, 68, 71, 75, 78, 81, 85, 88, 92, 95, 99, 102, 105, 109, 112, 116, 119, 122, 126, 129, 133, 136, 139, 143, 146, 150, 153, 157, 160, 163, 167, 170, 174, 177, 180, 184, 187, 191, 194, 198
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OFFSET

1,1


COMMENTS

It appears that the distance between the a(n)th triangular number and the nearest square is greater than floor(a(n)/2).  Ralf Stephan, Sep 14 2013
A080764(a(n)) = 0.  Reinhard Zumkeller, Jul 03 2015


REFERENCES

Fraenkel, Aviezri S., On the recurrence f(m+1)=b(m)f(m)f(m1) and applications. Discrete Math. 224 (2000), no. 13, 273279.
R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics. AddisonWesley, Reading, MA, 1990, p. 77.
Wen An Liu and Xiao Zhao, Adjoining to (s,t)Wythoff's game its Ppositions as moves, Discrete Applied Mathematics, Aug 27 2014; DOI: 10.1016/j.dam.2014.08.009. See Table 3.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS

T. D. Noe, Table of n, a(n) for n = 1..10000
L. Carlitz, R. Scoville and V. E. Hoggatt, Jr. Pellian representatives, Fibonacci Quarterly, 10, issue 5, 1972, 449488.
Ian G. Connell, A generalization of Wythoff's game, Canad. Math. Bull. 2 (1959) 181190
J. N. Cooper and A. W. N. Riasanovsky, On the Reciprocal of the Binary Generating Function for the Sum of Divisors, 2012; J. Int. Seq. 16 (2013) #13.1.8
A. S. Fraenkel, How to beat your Wythoff games' opponent on three fronts, Amer. Math. Monthly, 89 (1982), 353361 (the case a=2).
Eric Weisstein's World of Mathematics, Beatty Sequence.
Index entries for sequences related to Beatty sequences


MATHEMATICA

Table[Floor[n*(2 + Sqrt[2])], {n, 60}] (* Stefan Steinerberger, Apr 15 2006 *)
Array[Floor[#(2+Sqrt[2])]&, 60] (* Harvey P. Dale, Dec 01 2015 *)


PROG

(Haskell)
a001952 = floor . (* (sqrt 2 + 2)) . fromIntegral
 Reinhard Zumkeller, Jul 03 2015
(PARI) a(n)=2*n+sqrtint(2*n^2) \\ Charles R Greathouse IV, Jan 05 2016


CROSSREFS

Complement of A001951; equals A001951(n)+2*n.
A bisection of A094077.
Cf. A026250, A080764.
Sequence in context: A190007 A310052 A310053 * A189795 A145383 A258834
Adjacent sequences: A001949 A001950 A001951 * A001953 A001954 A001955


KEYWORD

nonn,easy,nice


AUTHOR

N. J. A. Sloane


STATUS

approved



