Development of |
|
liste_max:=100000; sieving:=proc (stelle, p) begin while (stelle<=liste_max) do erg:=liste[stelle]; while(erg mod p=0) do // Divison of the stored f(x) by the prime erg:=erg /p; end_while; liste[stelle]:=erg; stelle:=stelle+p; end_while; end_proc; // Calculation of the values of the polynom for x from 0 to liste_max for x from 0 to liste_max do p:=abs (a*x^2+b*x+c); while (p mod 2=0) p:=p/2; liste [x]:=p; end_for; for x from 0 to liste_max do p:=liste[x]; if (p>1) then // Printing the Primes print (x, p); // 1. Sieving sieving (x+p, p); t:=(-x-b/a) mod p;If you are interested in some better algorithms have a look at quadr_Sieb_x^2+1.php.
if t=0 then t:=p; end_if; // 2. Sieving sieving (t, p); end_if; end_for;
2. Mathematical background
Lemma: If p | f(x) then also p | f(x+p) and p | f(-x-b/a) a) p | f(x) <=> ax^2 + bx + c = 0 mod p p | f(x+p) <=> a(x+p)^2 + b(x+p) + c = 0 mod p <=> ax^2 + 2axp + ap^2 + bx + bp + c = 0 mod p <=> ax^2 + bx + c = 0 mod p Thus if p | f(x) then p | f(x+p) b) if b = 0 mod a p | f(x) <=> ax^2 + bx + c = 0 mod p p | f(-x-b/a) <=> a(-x-b/a)^2 + b(-x-b/a) + c = 0 mod p <=> ax^2 + 2bx + b^2/a - bx - b^2/a + c = 0 mod p <=> ax^2 + bx + c = 0 mod p Thus if p | f(x) then p | f(-x-b/a)3. Correctness of the algorithm
The proof for this polynom is similar to the proof for the polynom f(x)=x^2-4x+1. a) First terms for the polynom f(x) = x^2+62x-277
f(0)=277
f(1)=107
f(2)=149
f(3)=41
f(4)=13
f(5)=29
f(6)=131
f(7)=103
f(8)=283
f(9)=181
f(10)=443
f(11)=263
f(12)=47
f(13)=349
f(14)=787
f(15)=439
f(16)=971
f(17)=1
f(18)=1163
f(19)=631
f(20)=1
f(21)=733
f(22)=1571
f(23)=839
f(24)=1787
f(25)=73
f(26)=2011
f(27)=1063
f(28)=2243
f(29)=1181
f(30)=191
f(31)=1303
f(32)=2731
f(33)=1429
f(34)=1
f(35)=1559
f(36)=3251
f(37)=1693
f(38)=271
f(39)=1831
f(40)=3803
f(41)=1973
f(42)=4091
f(43)=163
f(44)=1
f(45)=2269
f(46)=4691
f(47)=2423
f(48)=5003
f(49)=89
f(50)=5323
f(51)=211
f(52)=5651
f(53)=2909
f(54)=5987
f(55)=3079
f(56)=487
f(57)=3253
f(58)=1
f(59)=1
f(60)=7043
f(61)=3613
f(62)=7411
f(63)=1
f(64)=599
f(65)=3989
f(66)=8171
f(67)=1
f(68)=8563
f(69)=337
f(70)=8963
f(71)=4583
f(72)=9371
f(73)=4789
f(74)=9787
f(75)=4999
f(76)=10211
f(77)=401
f(78)=367
f(79)=5431
f(80)=11083
f(81)=5653
f(82)=887
f(83)=5879
f(84)=11987
f(85)=1
f(86)=12451
f(87)=6343
f(88)=12923
f(89)=6581
f(90)=1031
f(91)=6823
f(92)=479
f(93)=7069
f(94)=14387
f(95)=563
f(96)=14891
f(97)=7573
f(98)=1
f(99)=1
b) Substitution of the polynom
The polynom f(x)=x^2+62x-277 could be written as f(y)= y^2-1238 with x=y-31
c) Backsubstitution Beside by backsubstitution you get an estimation for the huge of the primes with p | f(x) and p < f(x) f'(y)>(2y-1) with with y=x+31
f'(x)>2x+61