A225378 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 R.

2, 3, 7, 8, 10, 12, 13, 14, 15, 17, 18, 19, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 35, 37, 38, 39, 40, 41, 42, 43, 44, 45, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 61, 62, 63, 64

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..10000

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, A225377, A005228, A030124, A037257.

Sequence in context: A288696 A163517 A047532 * A028808 A029718 A206821

Adjacent sequences: A225375 A225376 A225377 * A225379 A225380 A225381

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