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Integer part of the height of an equilateral triangle with side length n.
6

%I #14 Jul 07 2023 14:53:20

%S 0,1,2,3,4,5,6,6,7,8,9,10,11,12,12,13,14,15,16,17,18,19,19,20,21,22,

%T 23,24,25,25,26,27,28,29,30,31,32,32,33,34,35,36,37,38,38,39,40,41,42,

%U 43,44,45,45,46,47,48,49,50,51,51,52,53,54,55,56,57,58,58,59,60,61,62,63

%N Integer part of the height of an equilateral triangle with side length n.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/EquilateralTriangle.html">Equilateral Triangle</a>

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Equilateral_triangle">Equilateral triangle</a>

%F a(n) = floor(n*sqrt(3)/2).

%F a(n) = floor(A022838(n)/2).

%F a(n)*A004526(n) <= A171971(n)

%F a(n)*A005843(n) <= A171972(n).

%o (PARI) a(n)=sqrtint(3*n^2\4) \\ _Charles R Greathouse IV_, Jan 06 2013

%Y Beatty sequence of A010527.

%Y Cf. A022838, A004526, A005843, A171971, A171972.

%K nonn,easy

%O 1,3

%A _Reinhard Zumkeller_, Jan 20 2010