A273969 Numbers n such that there exists a pair x,y, where x<y, x! = n and y! = n, that makes {x,y,n,n} an amicable multiset.

702240, 817740, 1156680, 1159200, 1811040, 2450448, 2570400, 2784600, 3534300, 3912480, 4228560, 4546080, 4702320, 5682600, 6902280, 7280280, 7469280, 7706160, 8225280, 8316000, 8465184, 8522640, 8639400, 9025380, 9256800, 9282000, 9492120, 9828000

Offset

1,1

Comments

We call the multiset {x,y,n,n} amicable iff sigma(x) = sigma(y) = sigma(n) = x+y+n+n. For the x values, see A273970. For the y values, see A273971.

If the condition x<y were dropped, the terms from A259306 would also belong here.

Links

John Cerkan, Table of n, a(n) for n = 1..8082

John Cerkan, Python code

Example

sigma(695520) = sigma(803040) = sigma(702240) = 695520 + 803040 + 702240 + 702240.

Crossrefs

Cf. A259302, A259303, A259304, A259305, A259306, A273970, A273971.

Sequence in context: A204496 A332850 A183835 * A203834 A234701 A140943

Adjacent sequences: A273966 A273967 A273968 * A273970 A273971 A273972

Keyword

nonn

Author

John Cerkan, Jul 17 2016

Status

approved