[seqfan] Re: OEIS page header image

[Peter Luschny]

> Nice! Would it look good to float the numbers for the Pascal triangle

The idea are the triangular numbers A000217, more precisely,
citing from Karl Menninger, "Number words and number symbols":

"The Greeks called the counting board or table abakion, ...,
the counters were called psephoi (pebbles).

In addition to placing them in the columns of the counting board,
the Greeks also arranged counters independently to form
'geometrical numbers' — triangles, right angles, squares, etc. "

http://oeis.org/wiki/User:Peter_Luschny/FigurateNumber