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A297207 3d-congruent numbers: positive integers n for which there exists a trirectangular tetrahedron having volume n and rational areas and sides. 0
13, 85, 104, 175, 308, 351, 490, 680, 832, 1400, 1625, 2295, 2464, 2808, 3179, 3920, 4459, 4725, 5440, 6656, 8316, 9295, 9477, 9724, 10625, 11200, 13000, 13230, 13475, 17303, 18360, 19712, 19760, 21875, 22464, 25432, 28561, 29155, 31360, 35672, 37800, 38500, 43520, 43875 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Ordered list of numbers A295507(i)*j^3 with i,j positive integers.

LINKS

Table of n, a(n) for n=1..44.

Eric Weisstein's World of Mathematics, Trirectangular Tetrahedron

EXAMPLE

a(1) = 13 = 13*1^3 = A295507(1)*A000578(1) is the volume of the trirectangular tetrahedron with sides: {240, 117, 44, 125, 244, 267}*1^3/15840.

a(3) = 104 = 13*2^3 = A295507(1)*A000578(2) is the volume of the trirectangular tetrahedron with sides: {240, 117, 44, 125, 244, 267}*2^3/15840.

CROSSREFS

Cf. A295507, A000578 (cubes).

Sequence in context: A301953 A321589 A225129 * A222491 A010025 A001848

Adjacent sequences:  A297204 A297205 A297206 * A297208 A297209 A297210

KEYWORD

nonn

AUTHOR

Ralf Steiner, Dec 27 2017

STATUS

approved

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Last modified May 21 14:54 EDT 2022. Contains 353921 sequences. (Running on oeis4.)