|
|
A032788
|
|
Numbers k such that k(k+1)(k+2)...(k+19) / (k+(k+1)+(k+2)+...+(k+19)) is an integer.
|
|
1
|
|
|
0, 1, 3, 4, 7, 8, 10, 13, 15, 16, 18, 19, 22, 23, 28, 29, 31, 33, 36, 38, 40, 43, 49, 50, 51, 53, 57, 58, 62, 64, 67, 73, 75, 76, 78, 84, 85, 88, 95, 101, 103, 106, 112, 113, 114, 118, 127, 128, 133, 135, 139, 148, 152, 153, 166, 169, 171, 172, 178, 183, 190
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,3
|
|
COMMENTS
|
(d-19)/2 where d >= 19 divides 85734032330071125. In particular, the sequence is finite. - Robert Israel, Jul 13 2018
|
|
LINKS
|
|
|
MAPLE
|
sort([seq((t-19)/2, t=select(`>=`, numtheory:-divisors(85734032330071125), 19))]); # Robert Israel, Jul 13 2018
|
|
MATHEMATICA
|
Select[Range[0, 300], IntegerQ[Times@@Range[#, #+19]/Total[Range[#, #+19]]]&] (* Harvey P. Dale, Sep 02 2016 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,fini,full
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|