[seqfan] A173279 and A173280

Robert Munafo mrob27 at gmail.com
Mon Feb 22 14:29:02 CET 2010

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

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.

 Robert Munafo  --  mrob.com

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