hyperFactorial

Computes the hyperfactorial of n: 1^1 * 2^2 * 3^3 * ... n^n

BigInt

hyperFactorial

(

ulong n

)

Examples

import std.array: array;
auto hfacs = iota(1, 6).map!(n => hyperFactorial(n)).array;
assert(hfacs == [1, 4, 108, 27648, 86400000]);