A083389 Numbers n such that the number formed by the digits of 2n sorted in descending order is equal to the sum of the divisors of n after the digits of each divisor have been sorted in descending order (all zeros dropped).

37, 163, 397, 4789, 16633, 19603, 19963, 31663, 48799, 49789, 166303, 169633, 196003, 199603, 478999, 489799, 497899, 497989, 499879, 1696033, 1966303, 1969633, 1999603, 3016963, 3019663, 3169603, 3169963, 4789999, 4798999

Offset

1,1

Comments

Primes with certain digits and various combinations of those digits along with any number of zeros inserted are members. E.g., primes of the form 196(0_z)3, or 3+49*2^(n+2)*5^n for n>1, etc. are in this sequence.

Links

Table of n, a(n) for n=1..29.

Example

a(2)=163 because the digits of 2*163 sorted descending are 632; the divisors of 163 are [1, 163] and 1+631 = 632.

Crossrefs

Sequence in context: A140011 A296156 A250842 * A142909 A269259 A269859

Adjacent sequences: A083386 A083387 A083388 * A083390 A083391 A083392

Keyword

base,nonn

Author

Jason Earls, Jun 11 2003

Extensions

More terms from Sean A. Irvine, May 27 2010

Status

approved