[seqfan] Re: A173279 and A173280

Klaus Brockhaus klaus-brockhaus at t-online.de
Mon Feb 22 15:43:45 CET 2010


... and does it make sense to repeat the %N line (essentially) in the %F 
line?

%N A173279 Triangle read by columns, factorial numbers A000142 in every column shifted down twice, for k>0.
%F A173279 Triangle by columns, factorial numbers A000142 in every column shifted down twice, for k>0.

%N A173280 Triangle by columns, factorial numbers A000142 in every column shifted down twice, for k>0.
%F A173280 Triangle by columns, factorial numbers A000142 in every column shifted down twice, for k>0.


Robert Munafo schrieb:
> I found an error in A173279: the 8th row of the triangle (the row starting
> with 5040) is duplicated.
>
> The description of A173279 seems wrong: given the explicit display of the
> triangle, the sequence is clearly "by rows" not "by columns". Also, a "by
> columns" reading of that triangle would simply be A0142 down the first
> column and would never reach the 2nd or subsequent columns.
>
> Also, the description of A173280 does not seem to match the terms: it bears
> the similar description to that of A173279 but does not seem to be a
> triangle by rows or by columns. it starts out like A136580 then differs by
> 0,2,2,10,18,88,...
>
> Perhaps Gary or someone else can provide a better explanation for A173280?
>
> I have submitted the change to remove the duplicated row in A173279 but am
> unsure about the description, given how many times a nonintuitive
> description turns out to be valid (albeit obscure) maths jargon.
>
>   





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