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A003623 From a 3-way splitting of positive integers: [[n*phi^2]*phi].
(Formerly M2715)
17
3, 8, 11, 16, 21, 24, 29, 32, 37, 42, 45, 50, 55, 58, 63, 66, 71, 76, 79, 84, 87, 92, 97, 100, 105, 110, 113, 118, 121, 126, 131, 134, 139, 144, 147, 152, 155, 160, 165, 168, 173, 176, 181, 186, 189, 194, 199, 202, 207, 210, 215, 220, 223, 228, 231, 236, 241, 244, 249 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Union of A001950 & A003622 & A003623 = A000027.

a(n) is odd if and only if n is odd.  [Clark Kimberling, Apr 21 2011]

A005614(a(n)-1)=1 and A005614(a(n))=1, n>=1. Because Wythoff AB-numbers (see the formula section) mark the first entry of pairs of 1s in the rabbit sequence A005614(n-1), n>=1. - From Wolfdieter Lang, Jun 28 2011.

REFERENCES

Fraenkel, Aviezri S., Complementary iterated floor words and the Flora game.  SIAM J. Discrete Math. 24 (2010), no. 2, 570-588. - From N. J. A. Sloane, May 06 2011

J. Roberts, Lure of the Integers, Math. Assoc. America, 1992, p. 10.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Nathaniel Johnston, Table of n, a(n) for n = 1..10000

Index entries for sequences related to Beatty sequences

FORMULA

a(n) = [n*phi] + [n*phi^2] = A000201(n) + A001950(n).

a(n)=2*[n*phi]+n.

a(n)=A(B(n)) with A(k):=A000201(k) and B(k):=A001950(k), k>=1 (Wythoff AB-numbers).

MAPLE

A003623:=proc(n) return floor(floor(n*(3+sqrt(5))/2)*(1+sqrt(5))/2); end:seq(A003623(n), n=1..59); # Nathaniel Johnston, Apr 21 2011

MATHEMATICA

f[n_] := Floor[ GoldenRatio * Floor[ n * GoldenRatio^2]]; Array[f, 47]

(* another *) Table[n+2Floor[n*GoldenRatio], {n, 1, 100}]

CROSSREFS

Cf. A003622.

Sequence in context: A047470 A184401 A190251 * A190463 A190435 A188032

Adjacent sequences:  A003620 A003621 A003622 * A003624 A003625 A003626

KEYWORD

nonn,nice,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Mira Bernstein

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Last modified February 16 07:10 EST 2012. Contains 205874 sequences.