[seqfan] About triangles of numbers in OEIS

N. J. A. Sloane njas at research.att.com
Mon Sep 5 15:44:05 CEST 2011


Dear Sequence Fans and Editors

There are many examples in mathematics where a triangle can be written in two ways, as
(these are the Stirling numbers of the second kind, but there are a huge number
of similar examples):

either

1
0 1
0 1 1
0 1 3 1
0 1 7 6 1
...

or, omitting the 0-th column, as

1
1 1
1 3 1
1 7 6 1
...

Triangles are read by rows to become an OEIS entry.
These become different sequences:
Either 1 0 1 0 1 1 0 1 3 1 0 1 7 6 1 ...
or 1 1 1 1 3 1 1 7 6 1 ...

It is the OEIS policy to include BOTH versions, with cross-references between them.

Please do not start deleting any of these entries.

I am writing this because A137432 should not have been deleted. Especially
since I had recently edited it. DON'T DO THIS.

NJAS



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