26422

Appears in sequences

• Number of inverse semigroups of order n, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).at n=8A001428
• Numbers m such that phi(m)=(d_1+d_2+...+d_k)*(d_1!+d_2!+...+d_k!) where d_1 d_2...d_k is the decimal expansion of m.at n=1A107119
• Arises in covering a graph by forests and a matching.at n=20A179259
• Number of binary sequences of length n having a conjugate at Hamming distance 2.at n=21A179674
• Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,1,1,0,0 for x=0,1,2,3,4.at n=8A197313
• Sphenic numbers k = p*q*r such that reversal(k) is also a sphenic number and reversal(k) = reversal(p)*reversal(q)*reversal(r).at n=22A242726
• Total number of nodes summed over all nonnegative lattice paths from (0,0) to (n,0) where the allowed steps at (x,y) are (1,v) with v in {-1,0,...,max(y,1)}.at n=10A333106
• G.f.: Sum_{n=-oo..+oo} x^(n^2) * C(x)^(6*n-9), where C(x) = 1 + x*C(x)^2 is the g.f. of the Catalan numbers (A000108).at n=19A356779