42168

Appears in sequences

• Sorted elements of table (A035002) of a(m,n) = sum(a(m-k,n), k=1..m-1)+sum(a(m,n-k), k=1..n-1).at n=47A035001
• Column 8 of array illustrated in A089574 and related to A034261.at n=5A109126
• Amicable triples: numbers such that sigma(x) = sigma(y) = sigma(z) = x+y+z, x<y<z. We order these triples according to the common value of sigma. Sequence gives z numbers.at n=4A125492
• Triangle read by rows: T(n,k) is the number of permutations of [n] having k cycles with at most 2 alternating runs (it is assumed that the smallest element of the cycle is in the first position), 0<=k<=n.at n=49A187247
• Triangular array read by rows: T(n,k) is the number of simple labeled graphs on n nodes with unicyclic components having exactly k nodes with degree 1; n>=3, 0<=k<=n-3.at n=16A217763
• 4-loop graph coloring a rectangular array: number of n X n 0..8 arrays where 0..8 label nodes of a graph with edges 0,1 1,2 2,0 0,3 3,4 4,0 0,5 5,6 6,0 0,7 7,8 8,0 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.at n=2A223289
• 4-loop graph coloring a rectangular array: number of n X 3 0..8 arrays where 0..8 label nodes of a graph with edges 0,1 1,2 2,0 0,3 3,4 4,0 0,5 5,6 6,0 0,7 7,8 8,0 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.at n=2A223292
• T(n,k)=4-loop graph coloring a rectangular array: number of nXk 0..8 arrays where 0..8 label nodes of a graph with edges 0,1 1,2 2,0 0,3 3,4 4,0 0,5 5,6 6,0 0,7 7,8 8,0 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.at n=12A223297
• Numbers that belong to at least one amicable tuple.at n=36A255215
• Number of nX4 0..1 arrays with every element unequal to 1, 2, 3, 6 or 8 king-move adjacent elements, with upper left element zero.at n=14A305485
• Numbers z such that there exist two integers 0<x<=y<=z such that (x^2/sigma(x)^2 + y^2/sigma(y)^2 + z^2/sigma(z)^2) * (x + y + z)^2 = x^2 + y^2 + z^2.at n=10A385749
• Numbers z such that there exist two integers 0<x<=y<=z such that sigma(x)*sigma(y)*sigma(z) = (x + y + z)^3.at n=12A386010