[seqfan] Re: New formula for A030101 ?

Marc LeBrun mlb at well.com
Sun Mar 16 18:42:08 CET 2014


>="Martin Møller Skarbiniks Pedersen" <martin at linux.com>
>   It looks like the sequences A030101 and f(x) in Euler Problem 463 are the
> same but I am
> not sure.
> 
>   A030101: a(n) is the number produced when n is converted to base 2,
> reversed and then converted back to base 10.
> 
>   Euler Problem 463:
>     f(1)=1, f(3)=3, f(2n)=f(n), f(4n+1)=2f(2n+1)-f(n),
> f(4n+3)=3f(2n+1)+2f(n)

I get f(7) = 11: f(7) = f(4*1+3) = 3f(3)+2f(1) = 3*3+2*1 = 9+1 = 11.

What is "Euler Problem 493"?  Google isn't helpful.

Please submit f to the OEIS.  I think it starts 1,1,3,1,5,3,11,1,9,5,17...

--MLB





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