

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

Christopher Carl Heckman, Table of n, a(n) for n = 1..10001


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

See A225376.


CROSSREFS

Cf. A225376, A225378, A005228, A030124, A037257.
Sequence in context: A155569 A189484 A155567 * A036667 A056016 A231997
Adjacent sequences: A225374 A225375 A225376 * A225378 A225379 A225380


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, May 12 2013, based on email from Christopher Carl Heckman, May 06 2013


EXTENSIONS

Corrected and edited by Christopher Carl Heckman, May 12 2013


STATUS

approved



