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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A109678 Sequence and first differences include all square numbers exactly once. 0
1, 5, 14, 30, 55, 91, 140, 204, 285, 385, 506, 650, 819, 1015, 1240, 1496, 1785, 2109, 2470, 2870, 3311, 3795, 4324, 4900, 5525, 6201, 6930, 7714, 8555, 9455, 10416, 11440, 12529, 13685, 14910, 16206, 17575, 19019, 20540, 22140, 23821, 25585 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This sequence diverges from A000330 as 4900 (which is 70^2) appears in the sequence itself - thus won't be added to any a(n).

LINKS

Table of n, a(n) for n=1..42.

EXAMPLE

Superpose sequence and first differences:

1 5 14 30 55 91 140 204 285 385 506 650 819 1015

.4.9..16..25..36..49...64...81...100...121...144...169...196

All square numbers appear once and only once, either in the sequence itself or in the first differences.

CROSSREFS

Sequence in context: A231681 A231685 A074784 * A000330 A266783 A266784

Adjacent sequences:  A109675 A109676 A109677 * A109679 A109680 A109681

KEYWORD

base,easy,nonn

AUTHOR

Eric Angelini, Aug 30 2005

EXTENSIONS

Two programs removed that were reproducing A000030 and therefore erroneous. - R. J. Mathar, Mar 06 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 July 21 04:27 EDT 2017. Contains 289632 sequences.