A087280 Solutions n of max(m+d(m))=n+2 for m<n; d(m) is the number of divisors of m.

5, 8, 10, 12, 24

Offset

1,1

Comments

It is not known if there are other terms. There are no more terms < 10^10.

References

R. K. Guy, Unsolved Problems in Number Theory, section B8.

Links

Table of n, a(n) for n=1..5.

Paul Erdos, Some Unconventional Problems in Number Theory, Mathematics Magazine, Vol. 52, No. 2, Mar., 1979, pp. 67-70. See Problem 4. p. 68.

Example

The largest value of m+d(m) for m < n=8 is 6+d(6)=10 = n+2, so 8 is in the sequence.

Crossrefs

Sequence in context: A332513 A314381 A325180 * A335495 A355569 A280537

Adjacent sequences: A087277 A087278 A087279 * A087281 A087282 A087283

Keyword

nonn,more

Author

Jud McCranie, Aug 28 2003

Status

approved