As alwayshere are so many ways! The following is based on the "inverse" of
*/"1 [ 0 1 2 +"1 0 i. 10
0 6 24 60 120 210 336 504 720 990
That is,
{:@>@}.@p.@(,&2 3 1)@- 0 6 24 60 120 210 336 504 720 990
0
1
2
3
4
5
6
7
8
9
u=. (= <.)@{:@>@}.@p.@(,&2 3 1)@-
u 0 6 24 60 120 210 336 504 720 990
1
1
1
1
1
1
1
1
1
1
Another obfuscated way is via the inverse discrete Fourier transform but I
will pass on that one.
PS. I see Bo Jacobi got a similar idea 5 minutes ago (oh,well).
On Thu, Aug 6, 2015 at 1:58 PM, Kip Murray <[email protected]> wrote:
> The number 720 is special: it is 8*9*10 the product of three
> successive non-negative integers. The first few special numbers are
>
> */"1 [ 0 1 2 +"1 0 i. 10
> 0 6 24 60 120 210 336 504 720 990
>
> Write a verb test that tests whether a non-negative integer is special:
>
> test 720
> 1
> test 0
> 1
> test 721
> 0
>
> --Kip Murray
>
>
>
> --
> Sent from Gmail Mobile
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