Amicable pairs: Difference between revisions
Content deleted Content added
MaiconSoft (talk | contribs) Added Delphi reference to Pascal code |
m Julia version 1.0+ update |
||
Line 2,364:
'''Functions'''
<lang Julia>using Memoize, Primes, Printf
@memoize function pcontrib(p::Int64, a::Int64)
n = one(p)
pcon = one(p)
Line 2,375 ⟶ 2,376:
end
@memoize function divisorsum(n::Int64)
dsum = one(n)
for (p, a) in factor(n)
Line 2,383 ⟶ 2,384:
end
</lang>
'''Main'''
It is safe to exclude primes from consideration; their proper divisor sum is always 1. Also, this code uses a minor trick to ensure that none of the numbers identified are above the limit. All numbers in the range are checked for an amicable partner, but the pair is cataloged only when the greater member is reached.
<lang Julia>
function amicables(L = 2*10^7)
acnt = 0
println("Amicable pairs not greater than ", L)
for i in 2:L
!isprime(i) || continue
j = divisorsum(i)
j < i && divisorsum(j) == i || continue
acnt += 1
println(@sprintf("%4d", acnt), " => ", j, ", ", i)
end
end
amicables()
</lang>{{out}}
<pre>
Amicable pairs not greater than
1 => 220, 284
2 => 1184, 1210
Line 2,417 ⟶ 2,412:
7 => 12285, 14595
8 => 17296, 18416
9 => 66928, 66992
10 => 67095, 71145
11 => 63020, 76084
12 => 69615, 87633
13 => 79750, 88730
14 => 122368, 123152
15 => 100485, 124155
16 => 122265, 139815
17 => 141664, 153176
18 => 142310, 168730
19 => 171856, 176336
20 => 176272, 180848
21 => 196724, 202444
22 => 185368, 203432
23 => 280540, 365084
24 => 308620, 389924
25 => 356408, 399592
26 => 319550, 430402
27 => 437456, 455344
28 => 469028, 486178
29 => 503056, 514736
30 => 522405, 525915
31 => 643336, 652664
32 => 600392, 669688
33 => 609928, 686072
34 => 624184, 691256
35 => 635624, 712216
36 => 667964, 783556
37 => 726104, 796696
38 => 802725, 863835
39 => 879712, 901424
40 => 898216, 980984
41 => 998104, 1043096
42 => 1077890, 1099390
43 => 947835, 1125765
44 => 1154450, 1189150
45 => 1185376, 1286744
46 => 1156870, 1292570
47 => 1280565, 1340235
48 => 1175265, 1438983
49 => 1392368, 1464592
50 => 1328470, 1483850
51 => 1358595, 1486845
52 => 1511930, 1598470
53 => 1466150, 1747930
54 => 1468324, 1749212
55 => 1798875, 1870245
56 => 1669910, 2062570
57 => 2082464, 2090656
58 => 2236570, 2429030
59 => 2723792, 2874064
60 => 2739704, 2928136
61 => 2652728, 2941672
62 => 2802416, 2947216
63 => 2728726, 3077354
64 => 2803580, 3716164
65 => 3276856, 3721544
66 => 3606850, 3892670
67 => 3805264, 4006736
68 => 3786904, 4300136
69 => 4238984, 4314616
70 => 4259750, 4445050
71 => 4246130, 4488910
72 => 4482765, 5120595
73 => 4604776, 5162744
74 => 5459176, 5495264
75 => 5123090, 5504110
76 => 5357625, 5684679
77 => 5232010, 5799542
78 => 5385310, 5812130
79 => 5147032, 5843048
80 => 5730615, 6088905
81 => 4532710, 6135962
82 => 5726072, 6369928
83 => 6329416, 6371384
84 => 6377175, 6680025
85 => 6993610, 7158710
86 => 6955216, 7418864
87 => 7275532, 7471508
88 => 5864660, 7489324
89 => 7489112, 7674088
90 => 7677248, 7684672
91 => 7800544, 7916696
92 => 7850512, 8052488
93 => 7288930, 8221598
94 => 8262136, 8369864
95 => 7577350, 8493050
96 => 9363584, 9437056
97 => 9071685, 9498555
98 => 9199496, 9592504
99 => 8619765, 9627915
100 => 9339704, 9892936
101 => 9660950, 10025290
102 => 8826070, 10043690
103 => 10254970, 10273670
104 => 8666860, 10638356
105 => 9206925, 10791795
106 => 10572550, 10854650
107 => 8754130, 10893230
108 => 10533296, 10949704
109 => 9491625, 10950615
110 => 9478910, 11049730
111 => 10596368, 11199112
112 => 9773505, 11791935
113 => 11498355, 12024045
114 => 10992735, 12070305
115 => 11252648, 12101272
116 => 11545616, 12247504
117 => 11693290, 12361622
118 => 12397552, 13136528
119 => 11173460, 13212076
120 => 11905504, 13337336
121 => 13921528, 13985672
122 => 10634085, 14084763
123 => 12707704, 14236136
124 => 13813150, 14310050
125 => 14311688, 14718712
126 => 15002464, 15334304
127 => 13671735, 15877065
128 => 14443730, 15882670
129 => 16137628, 16150628
130 => 15363832, 16517768
131 => 14654150, 16817050
132 => 15938055, 17308665
133 => 17257695, 17578785
134 => 17908064, 18017056
135 => 14426230, 18087818
136 => 18056312, 18166888
137 => 17041010, 19150222
138 => 18655744, 19154336
139 => 16871582, 19325698
140 => 17844255, 19895265
141 => 17754165, 19985355
</pre>
| |||