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A071396 Rounded total surface area of a regular octahedron with edge length n. 5
0, 3, 14, 31, 55, 87, 125, 170, 222, 281, 346, 419, 499, 585, 679, 779, 887, 1001, 1122, 1251, 1386, 1528, 1677, 1833, 1995, 2165, 2342, 2525, 2716, 2913, 3118, 3329, 3547, 3772, 4005, 4244, 4489, 4742, 5002, 5269, 5543, 5823, 6111, 6405, 6707, 7015, 7330 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

S. Selby, editor, CRC Basic Mathematical Tables, CRC Press, 1970, pp. 10-11.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..10000

Eric Weisstein's World of Mathematics, Octahedron

Eric Weisstein's World of Mathematics, Platonic Solid

FORMULA

a(n) = round(2 * n^2 * sqrt(3)).

EXAMPLE

a(3)=31 because round(2*3^2*sqrt(3)) = round(18*1.73205...) = round(31.1769...) = 31.

PROG

(PARI) for(n=0, 100, print1(round(2*n^2*sqrt(3)), ", "))

(MAGMA) [Round(2*n^2 * Sqrt(3)): n in [0..50]]; // Vincenzo Librandi, May 21 2011

CROSSREFS

Cf. A070169 (tetrahedron), A033581 (cube), A071397 (dodecahedron), A071398 (icosahedron), A071400 (volume of octahedron).

Sequence in context: A014696 A235137 A197944 * A032525 A294420 A197946

Adjacent sequences:  A071393 A071394 A071395 * A071397 A071398 A071399

KEYWORD

easy,nonn

AUTHOR

Rick L. Shepherd, May 23 2002

STATUS

approved

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Last modified March 21 21:34 EDT 2019. Contains 321382 sequences. (Running on oeis4.)