Fwd: OEIS backup: Supersubfactorials: partial product of positive subfactorials (A000166).

[Jonathan Post]

Due to njas' vacation, I've avoided submitting any sequences or
comments for some time now.  However, I could not resist this one, as
it nicely (to me) connects 3 seqs with A-numbers less than 200.

By the way, after over half an hour, there is no autoreply to my yahoo
email account, but I've been backing up submissions for a long time.
I don't know how many disappeared into the aether in the years before
I started the back-ups. I often am at a PC with no printer, so had no
printouts.

I've sometimes appeared on, and shall appear on, OEIS during the
vacation because of seqs being coauthored and/or edited before the
vacation was announced.

By chance, Labor Day is my birthday, which would have amused my late
mother. So I invite everyone to take my birthday as a day off your
day-jobs.

---------- Forwarded message ----------
From: jonathan post <jvospost2 at yahoo.com>
Date: Sep 1, 2007 2:09 PM
Subject: OEIS backup: Supersubfactorials: partial product of positive
subfactorials (A000166).
To: jvospost2 at yahoo.com, jvospost3 at gmail.com

NEW SEQUENCE FROM Jonathan Vos Post

%I A000001
%S A000001 1, 2, 18, 792, 209880, 389117520,
5771780174160, 770509566129663360,
1028600220910021528728960,
15104551945968674840127424147200,
2661646219535110627933754465838408595200,
6097280347195551752308726494566061864012209126400
%N A000001 Supersubfactorials: partial product of
positive subfactorials (A000166).
%C A000001 This is to subfactorials (A000166,
rencontres numbers, or derangements) as
superfactorials (A000178) are to factorials (A000142).
%F A000001 a(n) = PRODUCT[k = 2 to n] A000166(k).
%e A000001 a(2) = 1.
a(3) = 1 * 2 = 2.
a(4) = 1 * 2 * 9 = 18 = 2 * 3^2.
a(5) = 1 * 2 * 9 * 44 = 792 = 2^3 * 3^2 * 11.
a(6) = 1 * 2 * 9 * 44 * 265 = 209880 = 2^3 * 3^2 * 5 *
11 * 53.
a(7) = 1 * 2 * 9 * 44 * 265 * 1854 = 389117520 = 2^4 *
3^4 * 5 * 11 * 53 * 103.
%Y A000001 Cf. 000142, A000166, A000178.
%O A000001 2,2
%K A000001 ,easy,nonn,
%A A000001 Jonathan Vos Post (jvospost2 at yahoo.com),
Sep 01 2007
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