數學知識交流－ Recursive Sequence (4)
2012-11-04 2:59 am
回答 (3)
2012-11-04 6:35 pm
2012-11-04 7:46 pm
The final answer of Q7 can be expressed as !n
(Subfactorial)
(Subfactorial)
2012-11-04 10:22 am
(6)
b(1) = a(1) = 2(1) +1 = 3
b(2) = a(3) = 2(3) +1 = 7
b(3) = a(7) = 2(7) +1 = 15
b(4) = a(15) = 2(15) +1 = 31
b(n) = a( 1+2+4+...+2^(n-1) ) = a( 1(1 - 2^n) / (1-2) ) = a(2^n -1)
b(n) = 2( 2^n -1) +1 = 2^(n+1) -1
(7)
未諗到~~
b(1) = a(1) = 2(1) +1 = 3
b(2) = a(3) = 2(3) +1 = 7
b(3) = a(7) = 2(7) +1 = 15
b(4) = a(15) = 2(15) +1 = 31
b(n) = a( 1+2+4+...+2^(n-1) ) = a( 1(1 - 2^n) / (1-2) ) = a(2^n -1)
b(n) = 2( 2^n -1) +1 = 2^(n+1) -1
(7)
未諗到~~
參考: maeducation.edu.hk
收錄日期: 2021-04-13 19:06:14
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20121103000051KK00443