A274453 Products of distinct numbers in A052963.

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

Offset

1,1

Links

Clark Kimberling, Table of n, a(n) for n = 1..10000

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}];
Take[s, 2 z]  (* A274453 *)

Crossrefs

Cf. A160009, A274280, A274432, A274452.

Sequence in context: A064955 A352189 A101725 * A105370 A173694 A190459

Adjacent sequences: A274450 A274451 A274452 * A274454 A274455 A274456

Keyword

nonn,easy

Author

Clark Kimberling, Jun 23 2016

Status

approved