80100

Appears in sequences

• Consider the family of multigraphs enriched by the species of linear order. Sequence gives the triangle read by rows giving coefficients of polynomials arising from enumeration of those multigraphs on n edges, arcs and loops.at n=23A098288
• Numbers k such that the concatenation of k with 4*k gives a square.at n=13A115535
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of e.g.f. B(x)^k, where B(x) is the e.g.f. of A213109.at n=60A384802