55470

Appears in sequences

• Composite numbers k+1 such that k*phi(k+1) is a perfect square.at n=34A069068
• Sum of the largest two parts in the partitions of 4n into 4 parts with smallest part equal to 1.at n=22A239186
• Irregular triangle read by rows: T(n, k) is the number of chains of subspaces 0 < V_1 < ... < V_r = (F_4)^n, counted up to coordinate permutation, with dimension increments given by (any fixed permutation of) the parts of the k-th partition of n in Abramowitz-Stegun order.at n=24A348115