úÎ!Zd     !Copyright (c) 2018 Vanessa McHaleNone »fast-arithmetic\( !n \) H»:> derangement <$> [0..10] [1,0,1,2,9,44,265,1854,14833,133496,1334961]fast-arithmeticThe n.th Catalan number, with indexing beginning at 0. 8»:> catalan <$> [0..9] [1,1,2,5,14,42,132,429,1430,4862]fast-arithmetic \binom{n}{k} fast-arithmetic$Stirling numbers of the second kind.fast-arithmetic n!! fast-arithmeticpCompute the maximal number of regions obtained by joining \( n \) points about a circle by straight lines. See  https://oeis.org/A000127here.fast-arithmetic\( n \)Safe 1!Copyright (c) 2018 Vanessa McHaleNone(fast-arithmeticRadical of an integer fast-arithmetic O(\sqrt(n)) fast-arithmeticSee /http://mathworld.wolfram.com/PerfectNumber.htmlhere fast-arithmetic%Sum of proper divisors. May overflow. fast-arithmetic Number of distinct prime factors fast-arithmeticNumber of distinct divisors.fast-arithmeticEuler totient function.       .fast-arithmetic-0.6.4.0-LmWJQm0qywM7l8y4CrAJJqNumeric.CombinatoricsNumeric.NumberTheoryNumeric.Common derangementcatalanchoose permutations stirling2 factorialdoubleFactorial maxRegionsradicalisPrime isPerfect sumDivisors littleOmegatautotientasTest conjugate