344232domain: NAppears in sequencesIteration of unitary-sigma function: a(1) = 2, a(n) = usigma(a(n-1)).at n=30A059460Number of permutations of 1..n containing the relative rank sequence { 235164 } at any spacing.at n=4A159146Number of unlabeled P-series with n elements.at n=15A349276