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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A139098 8n^2. 19
0, 8, 32, 72, 128, 200, 288, 392, 512, 648, 800, 968, 1152, 1352, 1568, 1800, 2048, 2312, 2592, 2888, 3200, 3528, 3872, 4232, 4608, 5000, 5408, 5832, 6272, 6728, 7200, 7688, 8192, 8712, 9248, 9800, 10368, 10952, 11552, 12168, 12800 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Opposite numbers to the centered 16-gonal numbers (A069129) in the square spiral whose vertices are the triangular numbers (A000217).

8 times the squares. - Omar E. Pol, Dec 09 2008

a(n-1) is the molecular topological index of the n-wheel graph W_n. - Eric W. Weisstein, Jul 11 2011

An n * n pandiagonal magic square has a(n) orientations. - Kausthub Gudipati, Sep 15, 2011

Area of a square with diagonal 4n. - Wesley Ivan Hurt, Jun 19 2014

Sum of all the parts in the partitions of 4n into exactly two parts. - Wesley Ivan Hurt, Jul 23 2014

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..800

Omar E. Pol, Determinacion geometrica de los numeros primos y perfectos.

Eric Weisstein's World of Mathematics, Molecular Topological Index

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

FORMULA

a(n) = A000290(n)*8. - Omar E. Pol, Dec 09 2008

a(n) = A001105(n)*4 = A016742(n)*2. - Omar E. Pol, Dec 13 2008

G.f.: -8*x*(1+x) / (x-1)^3 . - R. J. Mathar, Nov 27 2015

MAPLE

A139098:=n->8*n^2; seq(A139098(n), n=0..50); # Wesley Ivan Hurt, Jun 19 2014

MATHEMATICA

s=0; lst={s}; Do[s+=n++ +8; AppendTo[lst, s], {n, 0, 8!, 16}]; lst (* Vladimir Joseph Stephan Orlovsky, Nov 16 2008 *)

8 Range[0, 50]^2 (* Wesley Ivan Hurt, Jun 19 2014 *)

PROG

(MAGMA) [8*n^2: n in [0..50]]; // Vincenzo Librandi, Apr 26 2011

CROSSREFS

Cf. A000217, A000290, A016766, A033582, A069129, A001105, A016742.

Sequence in context: A253295 A009245 A018842 * A224543 A211633 A130809

Adjacent sequences:  A139095 A139096 A139097 * A139099 A139100 A139101

KEYWORD

easy,nonn

AUTHOR

Omar E. Pol, Apr 25 2008

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 March 29 15:31 EDT 2017. Contains 284273 sequences.