[seqfan] Re: Q regarding comment in A000079 (Powers of 2)
Joerg Arndt
arndt at jjj.de
Tue Jun 30 08:42:19 CEST 2009
The fact that 2^n counts the subsets of the n-set is covered
by the very first comment. I deleted your comment.
cheers, jj
* lajos66 at t-online.hu <lajos66 at t-online.hu> [Jun 30. 2009 16:08]:
>
>
> Hungary:
> http://hu.wikipedia.org/wiki/Vari%C3%A1ci%C3%B3
>
> * Az n db. elem k-ad osztályú variációinak száma
> (jelölje V_n^k):
> V_n^k = \frac{n!}{(n-k)!} = n(n-1)\ldots (n-k+1)
> .
> * Az n db. elem k-ad osztályú ismétléses variációinak
> száma (jelölje V_n^{k,i}):
> V_n^{k,i} = n^k
>
> example, there :Two element
> * aa
> * ab
> * ba
> * bb
> 2^2= 4
>
> example, there :Three (3) element
>
> aaa, bbb, ccc, abc, acb, bac, bca, cab, cba, aab, aba,baa,
> aac, aca, caa, abb, bab, bba, bbc, bcb, cbb. acc, cac, cca,
> bcc, cbc, bcc. >>27
>
> 3^3= 27
>
> 4^4 = 64, etc...
>
> [...]
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