A071863 Numbers n such that sum of primes dividing n (with repetition) is equal to the largest prime factor of n+1.

54, 90, 328, 390, 423, 608, 1805, 1825, 2755, 2847, 3008, 3289, 3354, 5695, 8949, 9453, 9675, 9685, 10730, 10933, 12462, 12564, 12803, 15235, 18424, 20622, 28033, 29350, 33813, 39909, 41040, 41712, 43165, 50880, 57672, 57707, 59622, 63189

Offset

1,1

Comments

There are 159 such numbers up to 1 million. -Harvey P. Dale, May 24 2012

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..150 from Harvey P. Dale)

Example

1805 is a term because A001414(1805) = 5+19+19 = 43 and 1806 = 2*3*7*43.

Mathematica

Select[Range[65000], Total[Times@@@FactorInteger[#]]==FactorInteger[#+1][[-1, 1]]&] (* Harvey P. Dale, May 24 2012 *)

Crossrefs

Cf. A006530, A001414.

Sequence in context: A096512 A243542 A290146 * A045933 A088986 A259717

Adjacent sequences: A071860 A071861 A071862 * A071864 A071865 A071866

Keyword

nonn

Author

Jason Earls, Jun 09 2002

Status

approved