Yellowstone sequence: Difference between revisions

{{out}}

<pre>First 30 values in the yellowstone sequence:

[1, 2, 3, 4, 9, 8, 15, 14, 5, 6, 25, 12, 35, 16, 7, 10, 21, 20, 27, 22, 39, 11, 13, 33, 26, 45, 28, 51, 32, 17]</pre>

=={{header|Lua}}==

{{trans|Java}}

<lang lua>function gcd(a, b)

if b == 0 then

return a

end

return gcd(b, a % b)

end

function printArray(a)

io.write('[')

for i,v in pairs(a) do

if i > 1 then

io.write(', ')

end

io.write(v)

end

io.write(']')

return nil

end

function removeAt(a, i)

local na = {}

for j,v in pairs(a) do

if j ~= i then

table.insert(na, v)

end

end

return na

end

function yellowstone(sequenceCount)

local yellow = {1, 2, 3}

local num = 4

local notYellow = {}

local yellowSize = 3

while yellowSize < sequenceCount do

local found = -1

for i,test in pairs(notYellow) do

if gcd(yellow[yellowSize - 1], test) > 1 and gcd(yellow[yellowSize - 0], test) == 1 then

found = i

break

end

end

if found >= 0 then

table.insert(yellow, notYellow[found])

notYellow = removeAt(notYellow, found)

yellowSize = yellowSize + 1

else

while true do

if gcd(yellow[yellowSize - 1], num) > 1 and gcd(yellow[yellowSize - 0], num) == 1 then

table.insert(yellow, num)

yellowSize = yellowSize + 1

num = num + 1

break

end

table.insert(notYellow, num)

num = num + 1

end

end

end

return yellow

end

function main()

print("First 30 values in the yellowstone sequence:")

printArray(yellowstone(30))

print()

end

main()</lang>