|
|
A274453
|
|
Products of distinct numbers in A052963.
|
|
1
|
|
|
2, 5, 10, 14, 28, 40, 70, 80, 115, 140, 200, 230, 331, 400, 560, 575, 662, 953, 1120, 1150, 1610, 1655, 1906, 2744, 2800, 3220, 3310, 4600, 4634, 4765, 5488, 5600, 7901, 8050, 9200, 9268, 9530, 13240, 13342, 13720, 15802, 16100, 22750, 23000, 23170, 26480
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
EXAMPLE
|
The numbers in A274453 are 1, 2, 5, 14, 40, 115, 331,..., so that the sequence of all products of distinct members, in increasing order, is (2, 5, 10, 14, 28, 40, 70, 80,...).
|
|
MATHEMATICA
|
r[1] := 1; r[2] := 1; r[3] = 1; r[n_] := r[n] = 3 r[n - 1] - r[n - 3]
s = {1}; z = 30; f = Map[r, Range[z]]; Take[f, 20] (* A052963 *)
Do[s = Union[s, Select[s*f[[i]], # <= f[[z]] &]], {i, z}];
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|