Function zetaNegativeInteger

src/compute-engine/numerics/bernoulli.ts:105–110

(n: number)

 * the odd Bernoulli numbers B₃, B₅, … vanish).
 */
export function zetaNegativeInteger(n: number): [bigint, bigint] {
  if (!Number.isInteger(n) || n < 1)
    throw new RangeError(`zetaNegativeInteger: invalid index ${n}`);
  const [num, den] = bernoulliRational(n + 1);
  return reduce(-num, den * BigInt(n + 1));
}