login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A131647 Composite numbers that are products of distinct primes and divisible by the sum of those primes. 1
30, 70, 105, 231, 286, 627, 646, 805, 897, 1122, 1581, 1798, 2730, 2958, 2967, 3055, 3526, 3570, 4070, 4543, 5487, 5658, 6461, 6745, 7198, 7881, 8778, 8970, 9222, 9282, 9717, 10366, 10370, 10626, 10707, 11130, 14231, 15015, 16377, 16530, 19866 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

A131647 union A000040 = A005117 intersect A086486. - Ray Chandler, Nov 29 2011.

EXAMPLE

1122 = 2*3*11*17 and 1122 is divisible by 2+3+11+17=33.

MATHEMATICA

Select[Range[2, 20000], PrimeQ[ # ] == False && Union[Transpose[FactorInteger[ # ]][[2]]] == {1} && Mod[ #, Plus @@ Transpose[FactorInteger[ # ]][[1]]] == 0 &]

CROSSREFS

Sequence in context: A112343 A182996 A164596 * A071141 A071312 A071142

Adjacent sequences:  A131644 A131645 A131646 * A131648 A131649 A131650

KEYWORD

nonn

AUTHOR

Tanya Khovanova (tanyakh(AT)yahoo.com), Sep 08 2007

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 15 17:46 EST 2012. Contains 205835 sequences.