Erdös-Selfridge categorization of primes: Difference between revisions

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Category 11 => first: 8524807, total: 1, last:8524807
Category 11 => first: 8524807, total: 1, last:8524807
</pre>
</pre>

=={{header|Mathematica}}/{{header|Wolfram Language}}==
<lang Mathematica>ClearAll[SpecialPrimeFactors]
SpecialPrimeFactors[p_Integer] := FactorInteger[p + 1][[All, 1]]

ps = Prime[Range[200]];
cs = {{2, 3}};
Do[
If[Length[ps] > 0,
newc =
Select[ps,
Complement[SpecialPrimeFactors[#], Catenate[cs]] === {} &];
AppendTo[cs, newc];
ps = Complement[ps, newc];
,
Break[]
]
,
{n, 1, \[Infinity]}
];
Do[
Print["Category: ", i - 1];
Print@Multicolumn[cs[[i]], {Automatic, 10}]
,
{i, Length[cs]}
]


ps = Prime[Range[1000000]];
ps = Parallelize[{#, SpecialPrimeFactors[#]} & /@ ps];
cs = {{2, 3}};
Do[
If[Length[ps] > 0,
newcs = Last[cs];
ps[[All, 2]] = ps[[All, 2]] /. Dispatch[Thread[newcs -> Nothing]];
newc = Select[ps, Last/*Length/*EqualTo[0]];
ps = Complement[ps, newc];
newc = newc[[All, 1]];
AppendTo[cs, newc];
,
Break[]
]
,
{n, 1, \[Infinity]}
];

TableForm[{First[#], Last[#], Length[#]} & /@ Rest[cs],
TableHeadings -> {Automatic, {"First", "Last", "Count"}},
TableAlignments -> Right]</lang>
{{out}}
<pre>
Category: 0
2 3

Category: 1
2 5 11 23 47 71 127 383 647 971
3 7 17 31 53 107 191 431 863 1151

Category: 2
13 83 167 251 349 479 599 761 967 1223
19 89 179 263 359 499 619 769 991
29 97 197 269 367 503 641 809 1019
41 101 199 271 373 509 643 827 1033
43 109 211 281 419 557 659 839 1049
59 131 223 283 433 563 709 881 1069
61 137 229 293 439 577 719 919 1087
67 139 239 307 449 587 743 929 1103
79 149 241 317 461 593 751 953 1187

Category: 3
37 193 347 457 547 683 821 937 1051 1163
103 227 353 463 569 701 829 947 1061 1171
113 233 379 467 571 727 853 983 1063 1181
151 257 389 487 601 733 857 997 1091 1193
157 277 397 491 607 773 859 1009 1097 1217
163 311 401 521 613 787 877 1013 1117
173 331 409 523 631 797 883 1031 1123
181 337 421 541 653 811 911 1039 1153

Category: 4
73 443 661 677 739 823 907 977 1109 1201
313 617 673 691 757 887 941 1093 1129 1213

Category: 5
1021

First Last Count
1 2 10616831 46
2 13 15482669 10497
3 37 15485863 201987
4 73 15485849 413891
5 1021 15485837 263109
6 2917 15485857 87560
7 15013 15484631 19389
8 49681 15485621 3129
9 532801 15472811 363
10 1065601 15472321 28
11 8524807 8524807 1</pre>


=={{header|Perl}}==
=={{header|Perl}}==