login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A225386 Construct sequences P,Q,R by the rules: Q = first differences of P, R = second differences of P, P starts with 1,3,9, Q starts with 2,6, R starts with 4; at each stage the smallest number not yet present in P,Q,R is appended to R. Sequence gives Q. 4
2, 6, 11, 18, 26, 36, 48, 61, 75, 90, 106, 123, 142, 163, 185, 208, 232, 257, 284, 312, 341, 371, 402, 434, 467, 501, 536, 573, 612, 652, 693, 735, 778, 822, 867, 913, 960, 1009, 1059, 1110, 1162, 1215, 1269, 1324, 1380, 1437, 1495, 1554, 1614, 1676, 1739, 1804, 1870, 1937, 2005, 2074, 2144 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

In contrast to A225376-A225378, here it is not required (and not true) that each number should appear just once in P union Q union R. On the other hand, again in contrast to A225376-A225378, here it is obvious that P, Q, R are infinite.

The first three numbers that are repeated are 284, 2074, 3500, which appear in both P and Q. There may be no others. Of course R is disjoint from P and Q, by definition.

LINKS

Table of n, a(n) for n=1..57.

MAPLE

See A225385.

CROSSREFS

Cf. A225385, A225387, A005228, A030124, A037257, A225376, A225377, A225378.

Sequence in context: A239698 A039745 A248469 * A037258 A201993 A024521

Adjacent sequences:  A225383 A225384 A225385 * A225387 A225388 A225389

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, May 15 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified February 23 04:57 EST 2018. Contains 299473 sequences. (Running on oeis4.)