Numbers 140-149

A page of the Numeropedia - the Special Encyclopedia of Numbers

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140

[Math.]  A pyramidal number (sum of all squares of integers from 1 to 7): 140 = 12+22+32+42+52+62+72.

[Math.]  Each internal angle of a regular 9-sided polygon (nonagon or enneagon) is 140o.

[Math.]  Six square numbers using the same digits: 1302 = 16900, 1402 = 19600, 3102 = 96100, 1032 = 10609, 2472 = 61009 and 3012 = 90601.

[Tech.]  The numbers of automobile gear oil SAE viscosity: 75W, 80W, 80W-90, 85W, 90W and 140W.

[Tech.]  Automobile Tire’s Speed Rating

 Tire Rating L M N P Q R S Max. Speed (mph) Max. Speed (kph) 75 120 81 130 87 140 93 150 100 160 106 170 112 180 Tire Rating T U H V W Y Max. Speed (mph) Max. Speed (kph) 118 190 124 200 130 210 149 240 168 270 186 300

[World]  The ISO country code for Central African Republic. (ISO-3166)

[Tech.]  Volvo’s numbered series: 140 (142, 144, 145), 164, 240 (242, 244, 245), 260 (262, 264, 265), 340 (343, 345), 360, 440, 460, 480, 740, 760, 780, 850, 940 and 960. Digit 0 is replaced by the number of doors.

141

[Math.]  The 2nd Cullen prime number: 141´2141+1.

142

[Math.]  1423 = 2,863,288 = (28–6+32+88)3.

[Math.]  142,857´5 = 714,285 = 8572–1422, where 857,142 = 142,857´6.

[Math.]  Let f be a function f: N®N, where is N is the natural numbers, defined by: f(n+1) = f(n)/2 if f(n) is even and f(n+1) = 3f(n)+1 if f(n) is odd. It is conjectured that, for any seed value f(0), the sequence f(0), f(1), f(2),… will always end in 1, 4, 2,… which repeats infinitely. The conjecture is called the “(3n+1) problem”.

[Math.]

1×7 + 3 = 10

14×7 + 2 = 100

142×7 + 6 = 1000

1428×7 + 4 = 10000

14285×7 + 5 = 100000

142857×7 + 1 = 1000000

1428571×7 + 3 = 10000000

14285714×7 + 2 = 100000000

142857142×7 + 6 = 1000000000

1428571428×7 + 4 = 10000000000

14285714285×7 + 5 = 100000000000

142857142857×7 + 1 = 1000000000000

1428571428571×7 + 3 = 10000000000000

[Measure]  1 gill = 142.065375 ml (milliliters).

British imperial units for dry and liquid measures: 1 bushel = 4 pecks = 8 gallons = 32 quarts = 64 pints = 256 gills = 1280 fluidounces = 36.368736 liters.

143

[Math.]  1433 = 2,924,207 = (02+92+42+07)3.

[Math.]  The number of 3-digit prime numbers (from 101 to 997).

144

[Math.]  The 12th Fibonacci number and 122 = 144.

[Math.]  Reversible numbers and their squares: 122 = 144 and 212 = 441. Also: 1022 = 10404, 1202 = 14400, 2012 = 40401 and 2102 = 44100

[Math.]  Each internal angle of a regular 10-sided polygon (decagon) is 144o.

[Math.]  1445 = 1335+1105+845+275. (Lander & Parkin, 1966). The first counter-example to disprove Euler’s conjecture that it always requires at least n terms (of nth power) to sum to an nth power, nontrivially. (Fermat’s Last Theorem is a special case for only 2 terms).

[Math.]  144 = (1+4+4)×(1×4×4). The only other non-trivial such number is 135 (by D. Wilson). Also called Filzian numbers.

[Math.]  63504 = 441×144 = 2522.

[Measure]  The number of square inches in a square foot.

U.S. customary units for area measures: 1 acre = 160 square rods = 4,840 square yards = 43,560 square feet = 6,272,640 square inches = 4046.8564224 m2 & 1 square mile (1 section) = 640 acres = 2,589,988.11 m2 = 2.59 km2 = 259 hectares & 1 hectare = 2.471 acres = 10,000 m2 & 1 township = 36 square miles.

[Measure]  A gross = 12 dozens or 144.

[Measure]  A board foot (fbm), used for lumber, is 144 cubic inches (= 12 inch´12 inch´1 inch).

[World]  The ISO country code for Sri Lanka (was Ceylon). (ISO-3166)

144.3

[Measure]  Degrees Baumé is a unit of relative density, as read on hydrometer invented by the French chemist Antoine Baumé (1728-1804). For liquids lighter than water, the relative density d (degrees Baumé) = (144.3/S)–144.3, where s is specific gravity S; for heavier liquids, d = 144.3– (144.3/S).

145

[Math.]  145 = 1!+4!+5!. The only other non-trivial such number is 40,585 = 4!+0!+5!+8!+5!.

[Tech.]  Automobile tires used in the U.S. have tire section width of 145, 155, 165, 175, 185, 195, 205, 215, 225, 235, 245 or 255 (millimeters).

146

[Math.]  1463 = 3,112,136 = (–3+1+12+136)3 = (–3+11+2+136)3.

147

[Math.]  147 = 142–72 = (14+7)×7, where 14 = 7×2.

[Math.]  147×(14+7) = 143+73 = 3,087.

148

[Math.]  148× (14+8) = 143+83 = 3,256.

[Math.]  Three square numbers using the same digits: 1482 = 21904, 2032 = 41209 and 3022 = 91204.

[World]  The ISO country code for Chad. (ISO-3166)

149

[Math.]  A prime number.

[Math.]  40,578,660 = 2×2×3×3×5×17×89×149, where each digit 1-9 appears exactly twice.

[Tech.]  Automobile Tire’s Speed Rating

 Tire Rating L M N P Q R S Max. Speed (mph) Max. Speed (kph) 75 120 81 130 87 140 93 150 100 160 106 170 112 180 Tire Rating T U H V W Y Max. Speed (mph) Max. Speed (kph) 118 190 124 200 130 210 149 240 168 270 186 300

140-149

[Library]  Numbers 100-199 are the first 3 digits in Dewey Decimal Classification System call numbers for library books in Philosophy, Psychology and Ethics… Numbers 140-149 are for books in Special Philosophical Schools.

100-199

[Education] The numbers commonly assigned for upper level undergraduate (last 2 years, junior and senior) courses in most U.S. universities and colleges.