[seqfan] Further extensions to A005646, A[10]=208914

[Robert Munafo]

I now have the N=10 term (not yet verified), which is 208914. Andrew
Weimholt previously calculated A[9]=11847, which I verified. The algorithm
documented at http://mrob.com/pub/math/seq-a005646.html#alg2 takes just
under an hour to compute this on a single CPU.

"Franklin's Triangle" now looks like this:

  N=1   1
  N=2   0  1
  N=3   0  0  1
  N=4   0  0  1  2
  N=5   0  0  0  3   3
  N=6   0  0  0  3  17       6
  N=7   0  0  0  1  36      74      11
  N=8   0  0  0  1  60    573     358     23
  N=9   0  0  0  0  56  2802    7311   1631     47
 N=10  0  0  0  0  50 10087 107938 83170 7563 106

That last term (106) supports a conjecture linking this triangle to A000055.
Andrew Weimholt and I are corresponding about this, he has a better
understanding of the theory and is closer to proving it than I am.

-- 
 Robert Munafo  --  mrob.com