The Last Fermat's Theorem

Experiments

(search for related problems...)
You're reading an English translation of the original Czech page.

Fermat coefficients

In an effort to move closer to solutions of LF-theorem could therefore make sense to know the rules for sums of Fermat coefficients. Unlike the sequence of numbers np in a sequence of numbers f(n,p) sums exist. For given p we will write f(n,p) = f(n).

Sums of Fermat coefficients

In case pεP the numbers np indicate total number of instances in systems G(n,p). This number is approximately p times the number of self classes and numbers of self classes correspond to Fermat's coefficients. f(n,p) = (np−n)/p.

For p=2:

(a,b,c)       f(a)+f(b)= f(c)  (a,b,c)      f(a)+f(b)= f(c)
─────────────────────────────  ───────────────────────────
( 4,  6,  7)    6 + 15 = 21    ( 8, 28, 29)   28 +378 =406
( 5, 10, 11)   10 + 45 = 55    ( 9, 11, 14)   36 + 55 = 91 
( 6,  7,  9)   15 + 21 = 36    ( 9, 36, 37)   36 +630 =666
( 6, 15, 16)   15 +105 =120
( 7, 10, 12)   21 + 45 = 66 
( 7, 21, 22)   21 +210 =231

For p=3: For p=5:

(a,b,c)     f(a)+f(b)= f(c)    (a,b,c)  f(a)+f(b)= f(c)
───────────────────────────    ────────────────────────────
( 9, 15, 16)  240+1120 =1360   (13,16,17) 74256+209712=283968  
(21, 55, 56) 3080+55440=58520
(31, 56, 59) 9920+58520=68440

Size of addends

For higher values of Fermat coefficients it shows that to meet the equation f(a) + f(b) = f(c) both addends must be large enough. Values f(a), f(b) and therefore also a,b gradually flatten (to close levels). In the case of p = 2 for the solution (13, 78, 79); ie. 78 + 3003 = 3081, gives the ratio (a + b)/c the value of 1.15190.

Another solution is close to the value (a+b)/c = √2 = 21/2:

(1728,1768,2472)     1492128+1562028 =3054156  1,41424
(1738,1768,2479)     1509453+1562028 =3071481  1,41428
(1740,1794,2499)     1512930+1608321 =3121251  1,41417
(1751,1765,2486)     1532125+1556730 =3088855  1,41432

Similarly, in the case of p=3 ratio (a+b)/c grows towards the value 22/3.

( 923,1287,1429) 262109848+ 710581872 =972691720  1,54654
( 969,1002,1242) 303284080+ 335337002 =638621082  1,58696
(1352,1479,1787) 823774952+1078407920 =190218287  1,58422

Generally, from the relationship 2∙f(a) = f(c) it follows: a/c = 21/p tj.2a/c = 2(p−1)/p.

The decisive sequences

Sums in decisive sequences

We will call decisive sequence - the first difference sequence of a given arithmetical sequence. E.g. in the sequence of second powers it is the sequence R2 = {1,3,5,7,9,11,13,...} and in the sequence of third powers R3 = R3 = {1,7,19,37,61,91,127,.....} We are interested in what must be addends (of elements of decisive sequence), so that their sum is the k-th power of a number..

Eg. in sequence R3 (k=3):

Twoo addends:
-------------
3781+4219=8000 = 20^3
19+17557=17576 = 26^3
7651+25117=32768 = 11347+21421=32768 = 32^3
 ...
Numbers ...,20,26,32,... are of the form 2 + 6n = 2 + 2kn
Three addends:
-------------
7+91+631=37+61+631=61+271+397=91+169+469=127+271+331=...=729=9^3
7+1261+2107=19+919+2437=37+169+3169=37+547+2791=37+1387+1951=...=3375 = 15^3
19+331+8911=61+3781+5419=91+1519+7651=...=9261 =21^3
Numbers ..,9,15,21,... are of the form 3 + 6n = 3 + 2kn

A similar result is obtained for 4, 5 or more addends. Generally, for p addends, the resulting power has the form:

(p+2kn)^k

.

This is simply the consequence of the fact that if a^2+b^k=c^k, k ε P then a+b-c = 2kq, q ε N.