GoKawiilPozzo: A Fast Lucky Number Checker Pozzo tests large integers for luckiness. It is dramatically more efficient than its predecessors, increasing the number of values searched for several OEIS sequences by a factor of between 1,000 and 100,000,000.
What is a Lucky Number?
Lucky numbers are produced by a sieve. From the OEIS Wiki:
Start with a sequence of positive odd numbers:
1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, ...
The first nonunit survivor is 3 , so strike every third value in this list:
1, 3, [5], 7, 9, [11], 13, 15, [17], 19, 21, [23], 25, 27, [29], 31, ...
The next unused survivor is 7 , so strike every seventh value of the new list.
1, 3, 7, 9, 13, 15, [19], 21, 25, 27, 31, 33, 37, [39], 43, ...
The values that are never struck out are the lucky numbers:
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