Sadaaki Yoshimura |
Monday, July 11, 2016
Sunday, July 10, 2016
Saturday, July 9, 2016
Matt Parker: 145 and the Melancoil: Unhappy Numbers (アンハッピー数)
- Happification tree
- Unhappy numbers
- Melancoil numbers
Example:
145 -> 1^2 + 4^2 + 5^2 = 42 -> 4^2 + 2^2 = 20 -> 2^2 + 0^2 = 4 -> 4^2 = 16 -> 1^2 + 6^2 = 37 -> 3^2 + 7^2 = 58 -> 5^2 + 8^2 = 89 -> 8^2 + 9^2 = 145
ラベル:
Happy number,
ハッピー数
Roger Bowley: Special Magic Square (特別な魔方陣): 176
Special Magic Square:
25 18 51 82
81 52 15 28
12 21 88 55
58 85 22 11
ラベル:
Magic square,
魔方陣
Antonio Padilla & Ria Symonds: Googol and Googolplex (グーゴルとグーゴルプレックス)
Googol: 10^100
Googolplex: 10^10^100
Number of quantum states of a person: 10^10^70
ラベル:
Googol,
Googolplex,
Quantum state,
グーゴル,
グーゴルプレックス,
量子状態
Friday, July 8, 2016
James Grime: 23 and Football Birthdays: Birthday Problem (誕生日のパラドックス)
Command:
$ bc <<< 'scale=10;364/365 * 363/365 * 362/365 * 361/365 * 360/365 * 359/365 * 358/365 * 357/365 * 356/365 * 355/365 * 354/365 * 353/365 * 352/365 * 351/365 * 350/365 * 349/365 * 348/365 * 347/365 * 346/365 * 345/365 * 344/365 * 343/365'
Result:
.4927027648
ラベル:
Birthday problem,
誕生日のパラドックス
Ria Symonds: 7 and Happy Numbers (ハッピー数)
Example: 7
7
7^2 = 49
4^2 + 9^2 = 16 + 81 = 97
9^2 + 7^2 = 81 + 49 = 130
1^2 + 3^2 + 0^2 = 1 + 9 + 0 = 10
1^2 + 0^2 = 1 + 0 = 1
7 is a happy number
Example: 8
8
8^2 = 64
6^2 + 4^2 = 36 + 16 = 52
5^2 + 2^2 = 25 + 4 = 29
2^2 + 9^2 = 4 + 81 = 85
8^2 + 5^2 = 64 + 25 = 89
8^2 + 9^2 = 64 + 81 = 145
1^2 + 4^2 + 5^2 = 1 + 16 + 25 = 42
4^2 + 2^2 = 16 + 4 = 20
2^2 + 0^2 = 4 + 0 = 4
4^2 = 16
1^2 + 6^2 = 1 + 36 = 37
3^2 + 7^2 = 9 + 49 = 58
5^2 + 8^2 = 25 + 64 = 89
8 is not a happy number
ラベル:
Happy number,
ハッピー数
Subscribe to:
Posts (Atom)