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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A248928 Interleave (2*n+2)^2 with (2*n+3)^2, both listed n+1 times. 0
4, 9, 16, 16, 25, 25, 36, 36, 36, 49, 49, 49, 64, 64, 64, 64, 81, 81, 81, 81, 100, 100, 100, 100, 100, 121, 121, 121, 121, 121, 144, 144, 144, 144, 144, 144, 169, 169, 169, 169, 169, 169, 196, 196, 196, 196, 196, 196, 196, 225, 225, 225, 225, 225, 225, 225 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Discovered via Janet's sequence A167268: the result of adding to A167268 the smallest increasing sequence (2, 7, 10, 14, 19, 23, 26, 30, 34, 39, 43, 47, ...) as to get a sequence of nondecreasing squares.

Even terms: 4, 16, 16, 36, 36, 36, ... = 4*A093995(n+1).

Odd terms: (A131507(n) + 2)^2.

LINKS

Table of n, a(n) for n=0..55.

FORMULA

a(n) = A027434(n+1)^2.

EXAMPLE

Seen as an irregular triangle:

4;

9;

16, 16;

25, 25;

36, 36, 36;

49, 49, 49;

64, 64, 64, 64;

81, 81, 81, 81;

...

PROG

(PARI) vector(60, n, (sqrtint(4*n-3)+1)^2) \\ after Charles R Greathouse IV, Michel Marcus, Oct 27 2014

CROSSREFS

Cf. A000267, A007395, A027434, A093995, A131507, A167268.

Sequence in context: A313306 A313307 A313308 * A080819 A313309 A313310

Adjacent sequences:  A248925 A248926 A248927 * A248929 A248930 A248931

KEYWORD

nonn,tabf

AUTHOR

Paul Curtz, Oct 17 2014

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 19 04:34 EDT 2019. Contains 326109 sequences. (Running on oeis4.)