A200995 Numbers not expressible as a product of Lucas numbers.

5, 10, 13, 15, 17, 19, 20, 23, 25, 26, 30, 31, 34, 35, 37, 38, 39, 40, 41, 43, 45, 46, 50, 51, 52, 53, 55, 57, 59, 60, 61, 62, 65, 67, 68, 69, 70, 71, 73, 74, 75, 78, 79, 80, 82, 83, 85, 86, 89, 90, 91, 92, 93, 95, 97, 100, 101, 102, 103, 104, 105, 106, 107, 109

Offset

1,1

Comments

a(n+1) - a(n) <= 5 for all n.

Links

Arkadiusz Wesolowski, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Lucas Number

Index entries for Lucas sequences

Example

65 = 5*13 is not the product of Lucas numbers, so 65 is in the sequence.

Mathematica

listMultiply[lst_] := Take[Union@Flatten@Table[lst[[i]]*lst[[j]], {i, Length[lst]}, {j, i}], 46]; A200381 = Nest[listMultiply, LucasL@Range[0, 9], 3]; Complement[Range@Last[A200381], A200381]

Crossrefs

Cf. A000032. Complement of A200381.

Sequence in context: A073503 A313378 A226386 * A049197 A324928 A009000

Adjacent sequences: A200992 A200993 A200994 * A200996 A200997 A200998

Keyword

nonn

Author

Arkadiusz Wesolowski, Jan 07 2013

Status

approved