1,3

-3 <= 4*A171975(n) - 3*a(n) < 3;

a(n)*A171975(n) <= A007590(n);

floor(a(n)*A171971(n)/3) <= A171973(n).

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

Eric Weisstein's World of Mathematics, Tetrahedron

Wikipedia, Tetrahedron

Index entries for sequences related to Beatty sequences

a(n) = floor(n*sqrt(6)/3).

(Haskell)

a171974 = floor . (/ 3) . (* sqrt 6) . fromInteger

-- Reinhard Zumkeller, Dec 15 2012

Cf. A171972, A022840. Beatty sequence of A157697.

Cf. A007590, A171971, A171973, A171975.

Sequence in context: A120507 A303787 A090223 * A232748 A308936 A187737

Adjacent sequences: A171971 A171972 A171973 * A171975 A171976 A171977

nonn

Reinhard Zumkeller, Jan 20 2010

approved