Talk:Brazilian numbers: Difference between revisions

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(some observations hopefully to limit the need of tests)
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:: I also noticed the difference two days ago, and I assumed that my REXX version was incorrect and was trying to find what the problem was in my computer program; &nbsp; I was hoping somebody else would calculate the 100,000<sup>th</sup> Brazilian number and verify it (or not). &nbsp; &nbsp; -- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 19:23, 14 August 2019 (UTC)
:: I also noticed the difference two days ago, and I assumed that my REXX version was incorrect and was trying to find what the problem was in my computer program; &nbsp; I was hoping somebody else would calculate the 100,000<sup>th</sup> Brazilian number and verify it (or not). &nbsp; &nbsp; -- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 19:23, 14 August 2019 (UTC)
==some observations not proofs ==
I tried to check the maximal base needed for an odd brazilian number.<BR>
If a number is brazilian the maximal base to test is always less equal number / 3.<BR>
If a number is prime and brazilian then the maximal base is square root of number.<BR>
[https://tio.run/##lVRNb@IwEL3nV8yhhxhBl9JDV9BWKiSokdgEbehqV4iDSRwwGxzkmFZt1b@@rO04H/Rjq72AM29m3vjNeHY4j3DaSXbR4bDj2YrjLSw5fqIpxczfb5eE5wPr@cQbO@4YxtPRiwXwfPItcFxw3Mn01nuRqDsJ3QK4mU5nv6YujAI/DCauBn3HG79YUcZyIX3ge3DnOyFcwVm32x0oSzgJZiN/pky9gXWPuTSOsj0TYZqJHPqAOceP8@7pqfHsnC0gS@COMnHeUylovuN0S5quBU1LkmjfZZalBLOBZclrRiTecwIeo2Kq4kpS2t70wceC3hOVe2AtyYoyCSQ0TaM15rYhmvcW7ZA@kSyRFp0CdXrtaM3tgMe24HuCENKFQf8KdIkPa5oSoC0Kl1dwS1frKhLiTOJDQwXgjcFAc7oAsSaFuXbYqKQykxbPJN58kLYZV@k03yxUigSnORmUEIvsTZui4puw@NVB4QWqTfrHspI9iwTNGIzWJPp9k6Yh3hKHrqjIbabHp73EOWmqivpVLwrVOclFO1Yx8L760mGfiqOKVYwyFBzgeD9A8SjIZKqwjkZaKqLug46/hu5r7U2MjC79/8mlm2W/JUJweW0KqfoH4P70ZpWAzWupgSklrRT18mH5EA1D34jjKRGHxyIq6ko@T6k3/Fg9WbSp@RIu6grL@l4XpgP8TNhBHNvFUkDobViScVOGHHkQmeHo9MpJpMknY4Lem3YdVw5u4bxoqqqeAKeCpJVMZ91i6Mx/y3ygctTrJsv7ybFW@JfC2DIbBjWfRb2LSv4KLu/@TlON2kVXy/3C6hE/alJjFQGMpZB6cUyyhwY5UprqJ960GW0bNVL9uOVqLfeP3rJMnS7qF8A@30PJ8Qyipur1OijOrN1D9WiXDTnKj5pIEatuyv7zpjrDUU8W/a9IC316OPyJkhSv8kMnOP8L Try it online!]
<pre>// only primes are shown
number base base*base
13 3 9
31 2 4
43 6 36
73 8 64
127 2 4
157 12 144
211 14 196
241 15 225
307 17 289
421 20 400
463 21 441
601 24 576
757 27 729
1093 3 9
1123 33 1089
1483 38 1444
..
55987 6 36
60271 245 60025
60763 246 60516
71023 266 70756
74257 272 73984
77563 278 77284
78121 279 77841
82657 287 82369
83233 288 82944
84391 290 84100
86143 293 85849
88741 17 289
95791 309 95481
98911 314 98596
odd brazilian numbers 7 .. 100000 : 40428
slots: base/number
<=1/12 <= 2/12 <=3/12 <=4/12
30717 4013 2225 3473 0 0 0 0 0 0 0 0<pre>

Revision as of 07:20, 15 August 2019

wee discrepancy

Is it possible to be a little more specific regarding the "wee discrepancy" with the F# version? <lang fsharp> printfn "%d" (Seq.item 3999 (Brazilian())) </lang> prints 4618--Nigel Galloway (talk) 17:05, 14 August 2019 (UTC)

OK I think I've found it--Nigel Galloway (talk) 17:37, 14 August 2019 (UTC)
I also noticed the difference two days ago, and I assumed that my REXX version was incorrect and was trying to find what the problem was in my computer program;   I was hoping somebody else would calculate the 100,000th Brazilian number and verify it (or not).     -- Gerard Schildberger (talk) 19:23, 14 August 2019 (UTC)

some observations not proofs

I tried to check the maximal base needed for an odd brazilian number.
If a number is brazilian the maximal base to test is always less equal number / 3.
If a number is prime and brazilian then the maximal base is square root of number.
Try it online!

// only primes are shown
    number      base      base*base
        13         3         9
        31         2         4
        43         6        36
        73         8        64
       127         2         4
       157        12       144
       211        14       196
       241        15       225
       307        17       289
       421        20       400
       463        21       441
       601        24       576
       757        27       729
      1093         3         9
      1123        33      1089
      1483        38      1444
..
     55987         6        36
     60271       245     60025
     60763       246     60516
     71023       266     70756
     74257       272     73984
     77563       278     77284
     78121       279     77841
     82657       287     82369
     83233       288     82944
     84391       290     84100
     86143       293     85849
     88741        17       289
     95791       309     95481
     98911       314     98596
odd brazilian numbers 7 .. 100000 : 40428
slots:  base/number 
  <=1/12 <= 2/12  <=3/12  <=4/12
   30717    4013    2225    3473       0       0       0       0       0       0       0       0