Find adjacent primes which differ by a square integer: Difference between revisions
Find adjacent primes which differ by a square integer (view source)
Revision as of 19:18, 21 November 2021
, 2 years agojulia example
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Line 192:
240 IF Q = 1 THEN P2 = P: P = T: RETURN
250 GOTO 220</lang>
=={{header|Julia}}==
<lang julia>using Primes
function squareprimegaps(limit=10^11)
pri = primes(limit)
squares = Set([1; [x * x for x in 2:2:100]])
diffs = [pri[i] - pri[i - 1] for i in 2:length(pri)]
squarediffs = sort(unique(filter(n -> n in squares, diffs)))
println("Square prime gaps to $limit:")
for sq in squarediffs
i = findfirst(x -> x == sq, diffs)
n = count(x -> x == sq, diffs)
println("Square difference $sq: $n found. Example: ($(pri[i]), $(pri[i + 1])).")
end
end
squareprimegaps()
</lang>{{out}}
<pre>
Square prime gaps to 10000000000:
Square difference 1: 1 found. Example: (2, 3).
Square difference 4: 27409998 found. Example: (7, 11).
Square difference 16: 15888305 found. Example: (1831, 1847).
Square difference 36: 11593345 found. Example: (9551, 9587).
Square difference 64: 1434957 found. Example: (89689, 89753).
Square difference 100: 268933 found. Example: (396733, 396833).
Square difference 144: 35563 found. Example: (11981443, 11981587).
Square difference 196: 1254 found. Example: (70396393, 70396589).
Square difference 256: 41 found. Example: (1872851947, 1872852203).
</pre>
=={{header|PARI/GP}}==
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