Template:Sequence of the Day for January 20

Intended for: January 20, 2012

Timetable

• First draft entered by Daniel Forgues on January 20, 2012 ✓
• Draft to be reviewed by November 20, 2011
• Draft to be approved by December 20, 2011

Yesterday's SOTD * Tomorrow's SOTD

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A170739 Expansion of g.f.:

1  +  x 1  −  19 x

.

{ 1, 20, 380, 7220, 137180, 2606420, 49521980, 940917620, ... }

As a last resort, for any day of first month one might always use g.f.:

1  +  x 1  −  ( ‘day of month’  −  1) x

.