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185 (number)

From Wikipedia, the free encyclopedia
← 184 185 186 →
Cardinalone hundred eighty-five
Ordinal185th
(one hundred eighty-fifth)
Factorization5 × 37
Greek numeralΡΠΕ´
Roman numeralCLXXXV
Binary101110012
Ternary202123
Senary5056
Octal2718
Duodecimal13512
HexadecimalB916

185 (one hundred [and] eighty-five) is the natural number following 184 and preceding 186.

In mathematics

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There are 185 different directed graphs on four unlabeled vertices that have at least one sink vertex, with no outgoing edges,[1] 185 ways of permuting the squares of a grid of squares in such a way that each square is one unit away from its original position horizontally, vertically, or diagonally,[2] and 185 matroids on five labeled elements in which each element participates in at least one basis.[3]

The Spiral of Theodorus

The Spiral of Theodorus is formed by unit-length line segments that, together with the center point of the spiral, form right triangles. 185 of these right triangles fit within the first four turns of this spiral.[4]

See also

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References

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  1. ^ Sloane, N. J. A. (ed.). "Sequence A051421 (Number of digraphs on n unlabeled nodes with a sink (or, with a source))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  2. ^ Sloane, N. J. A. (ed.). "Sequence A189181 (Number of nX4 array permutations with each element making a single king move)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  3. ^ Sloane, N. J. A. (ed.). "Sequence A058712 (Number of loopless matroids on n labeled points)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  4. ^ Sloane, N. J. A. (ed.). "Sequence A137515 (Maximal number of right triangles in n turns of Pythagoras's snail)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.