Wagstaff primes: Difference between revisions

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@@ Line 103: / Line 103: @@
 {{out}}
-<pre> 1:    3 - 3 (1 digits)
+<pre>
-:    5 - 11 (2 digits)
+p = 3, m = 3
-:    7 - 43 (2 digits)
+p = 5, m = 11
-:   11 - 683 (3 digits)
+p = 7, m = 43
-:   13 - 2731 (4 digits)
+p = 11, m = 683
-:   17 - 43691 (5 digits)
+p = 13, m = 2731
-:   19 - 174763 (6 digits)
+p = 17, m = 43691
-:   23 - 2796203 (7 digits)
+p = 19, m = 174763
-:   31 - 715827883 (9 digits)
+p = 23, m = 2796203
-:   43 - 2932031007403 (13 digits)
+p = 31, m = 715827883
-:   61 - 768614336404564651 (18 digits)
+p = 43, m = 2932031007403
-:   79 - 2014876366...8195784363 (24 digits)
+p = 61, m = 768614336404564651
-:  101 - 8451004001...1135470251 (30 digits)
-:  127 - 5671372782...8628035243 (38 digits)
+p = 79, m = 2014876366...8195784363 (24 digits)
-:  167 - 6235740319...3121833643 (50 digits)
+p = 101, m = 8451004001...1135470251 (30 digits)
-:  191 - 1046183622...7339085483 (58 digits)
+p = 127, m = 5671372782...8628035243 (38 digits)
-:  199 - 2678230073...8805883563 (60 digits)
+p = 167, m = 6235740319...3121833643 (50 digits)
-:  313 - 5562466239...8130434731 (94 digits)
+p = 191, m = 1046183622...7339085483 (58 digits)
-:  347 - 9556244233...1903606443 (104 digits)
+p = 199, m = 2678230073...8805883563 (60 digits)
-:  701 - 3506757267...7823854251 (211 digits)
+p = 313, m = 5562466239...8130434731 (94 digits)
-: 1709 - 9619252724...9070528171 (514 digits)
+p = 347, m = 9556244233...1903606443 (104 digits)
-: 2617 - 2081504709...3435947691 (788 digits)
+p = 701, m = 3506757267...7823854251 (211 digits)
-: 3539 - 7379609820...6486497963 (1065 digits)
+p = 1709, m = 9619252724...9070528171 (514 digits)
-: 5807 - 4018496237...6663568043 (1748 digits)</pre>
+p = 2617, m = 2081504709...3435947691 (788 digits)
+p = 3539, m = 7379609820...6486497963 (1065 digits)
+p = 5807, m = 4018496237...6663568043 (1748 digits)
+</pre>
 =={{header|BASIC256}}==
@@ Line 476: / Line 481: @@
 3539  45.089
 5807 181.280</syntaxhighlight>
+=={{header|Julia}}==
+* Requires Primes.jl
+<syntaxhighlight lang=julia>
+using Primes
+function wagstaffpair(p::Integer)
+    isodd(p) || return (false, nothing)
+    isprime(p) || return (false, nothing)
+    m = (2^big(p) + 1) ÷ 3
+    isprime(m) || return (false, nothing)
+    return (true, m)
+end
+function findn_wagstaff_pairs(n_to_find::T) where T <: Integer
+    pairs = Tuple{T, BigInt}[]
+    count = 0
+    i = 2
+    while count < n_to_find
+        iswag, m = wagstaffpair(i)
+        iswag && push!(pairs, (i, m))
+        count += iswag
+        i += 1
+    end
+    return pairs
+end
+function println_wagstaff(pair; max_digit_display::Integer=20)
+    p, m = pair
+    mstr = string(m)
+    if length(mstr) > max_digit_display
+        umiddle = cld(max_digit_display, 2)
+        lmiddle = fld(max_digit_display, 2)
+        mstr = join((mstr[1:umiddle], "...", mstr[end-lmiddle+1:end],
+                    " ($(length(mstr)) digits)"))
+    end
+    println("p = $p, m = $mstr")
+end
+foreach(println_wagstaff, findn_wagstaff_pairs(24))
+</syntaxhighlight>
+<pre>
+p = 3, m = 3
+p = 5, m = 11
+p = 7, m = 43
+p = 11, m = 683
+p = 13, m = 2731
+p = 17, m = 43691
+p = 19, m = 174763
+p = 23, m = 2796203
+p = 31, m = 715827883
+p = 43, m = 2932031007403
+p = 61, m = 768614336404564651
+p = 79, m = 2014876366...8195784363 (24 digits)
+p = 101, m = 8451004001...1135470251 (30 digits)
+p = 127, m = 5671372782...8628035243 (38 digits)
+p = 167, m = 6235740319...3121833643 (50 digits)
+p = 191, m = 1046183622...7339085483 (58 digits)
+p = 199, m = 2678230073...8805883563 (60 digits)
+p = 313, m = 5562466239...8130434731 (94 digits)
+p = 347, m = 9556244233...1903606443 (104 digits)
+p = 701, m = 3506757267...7823854251 (211 digits)
+p = 1709, m = 9619252724...9070528171 (514 digits)
+p = 2617, m = 2081504709...3435947691 (788 digits)
+p = 3539, m = 7379609820...6486497963 (1065 digits)
+p = 5807, m = 4018496237...6663568043 (1748 digits)
+</pre>
 =={{header|Java}}==