A259303 Numbers n such that there exists an x!=n that makes {x,x,n} an amicable multiset.

1560, 7380, 20448, 20664, 22752, 23352, 25248, 26964, 35328, 51360, 100200, 104412, 108792, 135540, 156312, 192096, 232740, 252252, 278460, 310752, 362160, 401688, 492660, 543456, 548592, 588744, 659736, 732060, 767520, 826848, 998712, 999648, 1129440, 1129464

Offset

1,1

Comments

We call the multiset {x,x,n} amicable iff sigma(x)=sigma(n)=x+x+n.

For the x values, see A259302.

If the condition x!=n were dropped, the terms from A005820 would also belong here.

Links

John Cerkan, Table of n, a(n) for n = 1..1742

Prog

(PARI) isOK(n) = x=(sigma(n)-n)/2; x>0 && x!=n && denominator(x)==1 && sigma(x)==x+x+n;

Crossrefs

Cf. A005820, A259307, A259302, A259304, A259305, A259306, A125490.

Sequence in context: A092001 A069475 A158773 * A035865 A031800 A280354

Adjacent sequences: A259300 A259301 A259302 * A259304 A259305 A259306

Keyword

nonn

Author

Jeppe Stig Nielsen, Jun 23 2015

Status

approved