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Jan 2, 1999, 3:00:00 AM1/2/99

to Taylor, Bill -- Bill Taylor, Michael Chemistry Pent in O, letter to ed//chief reporter, Vicki Hyde (ed) nz Science mthly, pan...@actrix.gen.nz

--

don s mcdonald | loto adviser + maths | results / 640 pers'lised nos.

wellington2, new zealand | +64 4 389 6820.

hiNT R.eply-to: dsmc...@actrix.gen.nz

formerly don.mc...@welcom.gen.nz n.b. suppress ".ld".

On Sat, 2 Jan 1999, Don McDonald wrote:

>

> OBITUARY.

>

> Alan Robert BOYD

> number theorist

> d. Hamilton N.Z. 1.1.1 999,

> aged 47 years.

>

>

>

> The most prolific mathematician of the

> 20th century, Paul Erdos, described

> the mathematician species as a device

> for turning coffee into theorems.

>

> Judging by the cup stains on Alan Boyd's

> letters to me, Alan, who died this year, practised a lot of

> number theory. Just before Christmas 1998

> Alan requested a disk of Acorn computer

> programs from me; he wanted to hire a

> computer. Although I did a few short

> calculations for Alan, he usually produced

> his own printouts, photocopying one side

> of the paper and copying dozens of columns of figures

> by hand in pen or pencil on the reverse side.

> He was the human printer computer.

>

> Alan studied sequences of integers.

> Hati numbers are integers

>

> 2^a .3^ b.N

>

>

> where a+b is even, and N is a whole number

> not divisible by 2 or 3.

>

> A few Hati numbers are

> 1 = 2^0 .3^0 a+b= 0

> 4 = 2^2 a+b = 2

>

> 6 = 2^1 .3^1 a+b= 2

>

> 9= 3^ 2 a+b= 2

> and 20 = 2^2 .5. a+b= 2.

>

>

>

> On my kitchen wall Alan gave me a colour

> coded array of Hati nos. up to 100.

>

> Alan taught me about Panarithmic numbers

> and Boyd numbers and I introduced him to

> primitive roots. He gave me a program.

> Can you do this

> program on your computer? I could.

>

> Alan arrived on the doorstep of my

> Newtown, Wellington, bedsit flat from Dunedin.

> He may have seen my ads in nz science mthly

> magaz. and was referred to me by

> the maths dept at Canterbury University.

>

> Every year he travelled to the North

> Island for NZ Scrabble championships.

> And he visited contacts in Wellington,

> including a brother in Lower Hutt and

> myself.

>

> Later he moved to Hamilton. Another

> habit that Alan briefly pursued was

> mailing press cuttings about bizarre incidents

> or Court proceedings. His research was

> published rarely in NZ mathematics magazine.

>

> Alan was the first pedestrian killed on

> NZ roads in 1 January 1999. A Z (alpha and

> omega.) It is presumed that he was the

> victim of a hit-and-run driver.

>

> by

> DON S McDonald

>

> 63/5 hut chi son rd

> newtown wellington. 2

> new zealand

> call minder 64 (4) 389 6820.

>

>

> date: 27.12.98 15:33 nzdt.

> subject: nextprime bin(300,150)+185.

> ng: sci.math reference, finding large prime nos.

>

> PRIME p divides bin(2n,n) + mp

> IFF there exists any k >=0

> such that Floor(2n/p^k) = Odd.

>

> Whence, nextprime = 2^300/root(150pi)

> = bin(300,150) +185 = 9.384E88

> contains no prime factor < 300.

>

> bin = nCr = n! / r!(n-r)!

> power of

> .. in 300! 150!

> 2 150

> 4 75 37

>

> 3 100

> 9 33 16

>

> 5 60

> 25 12

> 125 2

>

> 7 42

> 49 6

>

> 37 8

>

> --

> / don.

> dsmc...@actrix.gen.nz

> (644 welgtn n. zeal) 389-6820.

>

>

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