# [seqfan] Re: Parking lot for bad drivers

Rob Pratt Rob.Pratt at sas.com
Fri Jul 17 21:57:23 CEST 2015

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-----Original Message-----
From: SeqFan [mailto:seqfan-bounces at list.seqfan.eu] On Behalf Of Bob Selcoe
Sent: Thursday, July 16, 2015 2:34 AM
To: Sequence Fanatics Discussion list
Subject: [seqfan] Re: Parking lot for bad drivers

Hi Rob & Seqfans,

Would you please provide a solution for A260090(15) = 85?  I can only see 84 as maximum.

Thanks,
Bob Selcoe

--------------------------------------------------
From: "Rob Pratt" <Rob.Pratt at sas.com>
Sent: Wednesday, July 15, 2015 3:41 PM
To: "Sequence Fanatics Discussion list" <seqfan at list.seqfan.eu>
Subject: [seqfan] Re: Parking lot for bad drivers

> At Neil's request, I created a new entry (will be
> http://oeis.org/A260090).  I described it in terms of attacking kings
> on a chessboard and conjectured a formula.
>
> -----Original Message-----
> From: Rob Pratt
> Sent: Wednesday, July 15, 2015 11:29 AM
> To: Sequence Fanatics Discussion list
> Subject: RE: [seqfan] Re: Parking lot for bad drivers
>
> And here’s a less trivial 26-car solution:
>
> XX_XX_XX
> ________
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> _______X
> X_X_X___
> X_X_X_XX
>
> For n in 1,...,8, I get the following, which is not in OEIS:
> 1, 2, 4, 8, 12, 16, 21, 26
>
> -----Original Message-----
> From: SeqFan [mailto:seqfan-bounces at list.seqfan.eu] On Behalf Of
> APPLEGATE, DAVID L (DAVID L)
> Sent: Wednesday, July 15, 2015 10:54 AM
> To: Sequence Fanatics Discussion list
> Subject: [seqfan] Re: Parking lot for bad drivers
>
> I wonder if I misunderstand the problem as well - as I understand the
> problem, there's a trivial 24-car solution for the 8x8 lot:
>
> XX_XX_XX
> ________
> XX_XX_XX
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> XX_XX_XX
> ________
> XX_XX_XX
> ________
>
> David Applegate
>
> -----Original Message-----
> From: SeqFan [mailto:seqfan-bounces at list.seqfan.eu] On Behalf Of Rob
> Pratt
> Sent: Wednesday, July 15, 2015 10:45 AM
> To: Sequence Fanatics Discussion list
> Subject: [seqfan] Re: Parking lot for bad drivers
>
> Sorry, I just realized that I misinterpreted your problem to mean no
> three in a row, so A181018 provides only an upper bound.
>
> -----Original Message-----
> From: Rob Pratt
> Sent: Wednesday, July 15, 2015 10:42 AM
> To: 'Sequence Fanatics Discussion list'
> Subject: RE: [seqfan] Parking lot for bad drivers
>
> https://oeis.org/A181018
>
> -----Original Message-----
> From: SeqFan [mailto:seqfan-bounces at list.seqfan.eu] On Behalf Of Dale
> Gerdemann
> Sent: Wednesday, July 15, 2015 6:22 AM
> To: Sequence Fanatics Discussion list
> Subject: [seqfan] Parking lot for bad drivers
>
> Hello seqfans,
>
> Here's a puzzle from p. 39 of "Let's be Less Stupid" by Patricia Marx:
>
> At the parking lot for bad drivers, you are not allowed to park in a
> spot that is next to two occupied spots. In other words, no three cars
> can be contiguous--vertically, horizontally, or diagonally. ... How
> many cars can the lot fit.
>
> As an example, the book shows an 8x8 "parking lot" (looks like a
> chessboard) and gives a solution fitting 16 cars into this lot.
>
> Is this in the OEIS?
>
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