[seqfan] Re: Happy 10 - 9 + 8 * 7 * 6! / 5 / 4 + 3! / 2 * 1!

[MARION]

And a Happy 1234 - .5*6 + 789 as well

Let a(n) = 1 if the numbers from 1 to n can be arranged in forwards or backwards order to get 2020; 0 if not. Thus a(10) = 1 and a(9) = 1.

I will NOT be contriuting this sequence for inclusion in the OEIS, but I will spend a little time searching for a(8).

> On December 31, 2019 at 3:52 PM Bob Lyons <boblyonsnj at gmail.com> wrote:
> 
> 
> Happy New Year!
> 
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