If divides the numerator of the Bernoulli number for , then is called an irregular pair. For , the irregular pairs of various forms are for , for , none for , and for .
Irregular Pair
See also
Bernoulli Number, Irregular PrimeExplore with Wolfram|Alpha
References
Johnson, W. "Irregular Primes and Cyclotomic Invariants." Math. Comput. 29, 113-120, 1975.Referenced on Wolfram|Alpha
Irregular PairCite this as:
Weisstein, Eric W. "Irregular Pair." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/IrregularPair.html