

A178850


Lexicographically earliest infinite sequence such that (a(i)a(j)) mod (a(k)a(j)) is nonzero whenever i,j,k are disjoint.


0



1, 3, 6, 10, 20, 32, 112, 184, 232, 268, 364, 508, 2308, 3028, 5332, 8212, 46372, 75892, 106852, 116212, 191812, 222052, 265252, 298372, 315652, 328612, 361012, 401332, 444532, 507172, 635332, 706612, 787252, 943492, 1147252, 1210612, 1270372
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OFFSET

1,2


COMMENTS

First infinite picketfence sequence: a picket fence extended from any pair in the set encounters no other member of the set.
Terms in this sequence gradually become restricted in increasing moduli. From a(7) on, all terms are == 4 (mod 12).


LINKS

Table of n, a(n) for n=1..37.


EXAMPLE

From the initial 1,3, no further terms can be odd. After 3,6, no further multiples of 3 are possible. After 1,3,6, an 8 would be legal, except that no further extension of the sequence is then possible.


CROSSREFS

Cf. A178758.
Sequence in context: A058356 A270048 A295719 * A018171 A306357 A122628
Adjacent sequences: A178847 A178848 A178849 * A178851 A178852 A178853


KEYWORD

nonn


AUTHOR

Franklin T. AdamsWatters, Jun 18 2010


EXTENSIONS

More terms from Jon E. Schoenfield, Jun 25 2010


STATUS

approved



