208 (number)

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
← 207 208 209 →
Cardinaltwo hundred eight
Ordinal208th
(two hundred eighth)
Factorization24× 13
Greek numeralΣΗ´
Roman numeralCCVIII
Binary110100002
Ternary212013
Quaternary31004
Quinary13135
Senary5446
Octal3208
Duodecimal15412
HexadecimalD016
VigesimalA820
Base 365S36

208 (two hundred [and] eight) is the natural number following 207 and preceding 209.

208 is a practical number,[1] a tetranacci number,[2][3] a rhombic matchstick number,[4] a happy number, and a member of Aronson's sequence.[5] There are exactly 208 five-bead necklaces drawn from a set of beads with four colors,[6] and 208 generalized weak orders on three labeled points.[7][8]

References[edit]

  1. ^ Sloane, N. J. A. (ed.). "Sequence A005153 (Practical numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  2. ^ Sloane, N. J. A. (ed.). "Sequence A000078 (Tetranacci numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  3. ^ Waddill, Marcellus E. (1992), "The Tetranacci sequence and generalizations" (PDF), The Fibonacci Quarterly, 30 (1): 9–20, MR 1146535.
  4. ^ Sloane, N. J. A. (ed.). "Sequence A045944 (Rhombic matchstick numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  5. ^ Sloane, N. J. A. (ed.). "Sequence A005224 (T is the first, fourth, eleventh, ... letter in this sentence, not counting spaces or commas (Aronson's sequence))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  6. ^ Sloane, N. J. A. (ed.). "Sequence A001868 (Number of n-bead necklaces with 4 colors)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  7. ^ Sloane, N. J. A. (ed.). "Sequence A004121 (Generalized weak orders on n points)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  8. ^ Wagner, Carl G. (1982), "Enumeration of generalized weak orders", Archiv der Mathematik, 39 (2): 147–152, doi:10.1007/BF01899195, MR 0675654.