Numerator of the harmonic mean of the first n pentagonal numbers.

A250327

Numerator of the harmonic mean of the first n pentagonal numbers.

Terms

    a(0) =1a(1) =5a(2) =180a(3) =2640a(4) =23100a(5) =157080a(6) =183260a(7) =2408560a(8) =317026710a(9) =10215305100a(10) =89894684880a(11) =19613385792a(12) =403708857552

External references