A 74HC4017 decade counter has 10 outputs ,
one output 25mA high at a time ,
with max V+ of 6 VDC .
Thus each 74HC4017 output can light 3 series LED's .

Chris W wrote:

I want to flash LED's in an interesting sequence and was wondering if
there some pre made device that could do this of if it could be made
with out too much difficulty. It's hard to describe the sequence so I
will use ascii art to show the sequence. O = on, X = off.

OOOXXXXXXX
XOOOXXXXXX
XXOOOXXXXX
XXXOOOXXXX
XXXXOOOXXX
XXXXXOOOXX
XXXXXXOOOX
XXXXXXXOOO

Then repeat or maybe reverse it and then repeat. This shows 10 LEDs,
but I may be using 15 or 20.