A259304 Numbers n such that there exists an x!=n that makes {n,n,n,x} an amicable multiset.

796320, 1205820, 1277640, 1963080, 5154240, 8599500, 8694000, 9022860, 10820880, 12149280, 15845760, 17173800, 18023040, 19323360, 21360240, 22720320, 25494480, 27052200, 27335880, 28365480, 28574280, 28704060, 29211000, 30329640, 30373200, 30450420, 31433220

Offset

1,1

Comments

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

For the x values, see A259305.

If the condition x!=n were dropped, the terms from A027687 would also belong here.

Links

John Cerkan, Table of n, a(n) for n = 1..1000

Prog

(PARI) isOK(n) = x=sigma(n)-3*n; x>0&x!=n&sigma(x)==3*n+x

Crossrefs

Cf. A027687, A259307, A259305, A259302, A259303, A259306, A036471.

Sequence in context: A255762 A255755 A254844 * A151561 A022203 A234784

Adjacent sequences: A259301 A259302 A259303 * A259305 A259306 A259307

Keyword

nonn

Author

Jeppe Stig Nielsen, Jun 23 2015

Status

approved