

A225377


Construct sequences P,Q,R by the rules: Q = first differences of P, R = second differences of P, P starts with 1,5,11, Q starts with 4,6, R starts with 2; at each stage the smallest number not yet present in P,Q,R is appended to R; every number appears exactly once in the union of P,Q,R. Sequence gives Q.


8



4, 6, 9, 16, 24, 34, 46, 59, 73, 88, 105, 123, 142, 163, 185, 208, 233, 259, 286, 314, 343, 373, 404, 436, 469, 504, 541, 579, 618, 658, 699, 741, 784, 828, 873, 920, 968, 1017, 1067, 1118, 1170
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OFFSET

1,1


COMMENTS

P can be extended for 10^6 terms, but it is not known if P,Q,R can be extended to infinity.
A probabilistic argument suggests that P, Q, R are infinite.  N. J. A. Sloane, May 19 2013


LINKS



EXAMPLE

The initial terms of P, Q, R are:
1 5 11 20 36 60 94 140 199 272 360
4 6 9 16 24 34 46 59 73 88
2 3 7 8 10 12 13 14 15


MAPLE



CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



