jueves, 26 de enero de 2012

Products anagram


Since I was a kid, I have  always been amazed by the fact that when multiplying  four or seven by three, the two products obtained have the same digits but in a different position.
3 x 4 = 12
3 x 7 = 21

Now that I'm a little older, not much, it still surprises me that there are numbers that when they are multiplied by two different numbers, its products are a permutation of each other. Apparently you can find a number for each pair of distinct numbers provided that one of these numbers is not a multiple of ten of the other (ie for n and n * 10 ^ m, there is no number that when multiplied by a specific number, its products are not  anagrams).

Two years ago I published  8 sequences based on these facts in the OEIS. The title of each of these sequences is:  a(n) =smallest number such a(n)*n is an anagram of a(n)* X .

For example the sequence for X  equal to four is :
1782, 62937, 54, 1, 2826, 891, 3, 269, 631, 324, 2718, 4311, 3681, 37, 387, 25974, 4401, 477, 45, 48, 256437, 3393, 37, 26523, 3465, 3252, 3699, 34623, 2922, 27972, 27, 271, 284787, 27324, 25971, 263223, 26973, 25974, 2579247, 2514744     (OEIS A175693)

So:

1782   x 1 =      1782    and    1782 x 4 = 7218
62937 x 2 = 125874    and  62937 x 4 = 251748
54        x 3 =       162     and        54 x 4 = 216 
and so on.

Sometimes the same number meets the condition for example:
37 x 13 = 481, 37 x 22 = 814, 37 x 4 = 148

If we write these numbers in a table:

.
123456789
.
1112587410351782142857138613591139671089
.
21258741178262937543651757748919
.
3103517821543641958459345
.
417826293754128268913269631324
.
51428575436362826192792522439
.
613865175419588919169327594
.
71359774453279693131518
.
81139678919269631252273151297
.
9108993453242439594182971
.
.
389350202879452653384491541355073434873853905116


we can see that even though the values ​​are different, oddly enough, the sum of the values ​​of number one is an anagram to the sum of the values ​​of the number eight: 389350 - 385390

domingo, 22 de enero de 2012


The name of the numbers in English begins with one of these 13 letters : O,T,F,S,E,N,H,M,B,Q,U,D or G
So, the smallest numbers that start with different N letters in English are :

1                         1 One
2                       21 Twenty One
3                     102 One Hundred Two
4                     124 One Hundred Twenty Four
5                  1.146 One Thousand one Hundred Forty Six
6                  1.468 One Thousand Four Hundred Sixty Eight
7                41.689 Forty One Thousands Six Hundred Eighty Nine
8           1.004.689 One Million Four Thousands Six Hundred Eighty Nine
9    1.002.040.689 One Billion Two Millions Forty thousands Six Hundred Eighty Nine
10                          One Quadrillion one Billion Two Millions Forty thousands Six Hundred Eighty Nine
11                          One Undecillion one Quadrillion one Billion Two Millions Forty thousands Six Hundred Eighty Nine
12                          One Duodecillion one Undecillion one Quadrillion one Billion Two Millions Forty Thousands Six Hundred Eighty Nine
13                          One Googol one Duodecillion one Undecillion one Quadrillion one Billion Two Millions Forty Thousands Six Hundred Eighty Nine

lunes, 26 de septiembre de 2011

Numbers and letters

Write the natural numbers in English : one, two, three, four, etc


One has the first o, the first n, and the first e
Two has the second o
Three has the third e


And :


11 has the 11 e 
(onE two thrEE four fivE six sEvEn Eight NinE tEn ElEvEn)
23 has the 23 t
24 has the 24 t
29 has the 29 n
31 has the 31 n
108 has the 108 n
109 has the 109 n
198 has the 198 d
199 has the 199 d
240 has the 240 r
241 has the 241 r
243 has the 243 h
244 has the 244 h
245 has the 245 h
246 has the 246 h
247 has the 247 h
248 has the 248 h
249 has the 249 o
250 has the 250 o
251 has the 251 o
453 has the 453 u
454 has the 454 u
559 has the 559 i
1174 has the 1174 o
1716 has the 1716 s
5556 has the 5556 f
5557 has the 5557 f
6956 has the 6956 f
6957 has the 6957 f
15756 has the 15756 f
17155 has the 17155 f
24998 has the 24998 y
24999 has the 24999 y
43568 has the 43568 f
43569 has the 43569 f
735759 has the 735759 v
1105805 has the 1105805 v
1105806 has the 1105806 v
1105807 has the 1105807 v
1107784 has the 1107784 v
1107785 has the 1107785 v
1584503 has the 1584503 v
1584504 has the 1584504 v
1707940 has the 1707940 v
1707941 has the 1707941 v
1921566 has the 1921566 l
1921567 has the 1921567 l


I search until 2000000