81048domain: NAppears in sequencesSusceptibility series H_4 for 2-dimensional Ising model (divided by 2) for 1 particle excitation.at n=13A055920a(n) = |{m : multiplicative order of 5 mod m=n}|.at n=53A059887Weighted sum of the harmonic numbers.at n=6A087751Wiener index of the n X n knight graph.at n=10A292054