This site is supported by donations to The OEIS Foundation.

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A008527 Coordination sequence for body-centered tetragonal lattice. 19
 1, 10, 34, 74, 130, 202, 290, 394, 514, 650, 802, 970, 1154, 1354, 1570, 1802, 2050, 2314, 2594, 2890, 3202, 3530, 3874, 4234, 4610, 5002, 5410, 5834, 6274, 6730, 7202, 7690, 8194, 8714, 9250, 9802 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Also sequence found by reading the segment (1, 10) together with the line from 10, in the direction 10, 34,..., in the square spiral whose vertices are the generalized hexagonal numbers A000217. - Omar E. Pol, Nov 02 2012 REFERENCES M. O'Keeffe, Coordination sequences for lattices, Zeit. f. Krist., 210 (1995), 905-908. LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..10000 M. O'Keeffe, Coordination sequences for lattices, Zeit. f. Krist., 210 (1995), 905-908. [Annotated scanned copy] FORMULA a(0) = 1; a(n) = 8*n^2+2 for n>0. a(n) = (2n+1)^2 + (2n-1)^2 for n>0. Binomial transform of [1, 9, 15, 1, -1, 1, -1, 1,...]. - Gary W. Adamson, Dec 27 2007 a(n) = 3*a(n-1)-3*a(n-2)+a(n-3) for n>3. G.f.: (1+x)*(1+6*x+x^2)/(1-x)^3. [Colin Barker, Apr 13 2012] MAPLE [ seq( 8*k^2+2, k=0..40) ]; MATHEMATICA a[0] := 1; a[n_] := 8n^2 + 2; Table[a[n], {n, 0, 35}] (* Alonso del Arte, Sep 06 2011 *) CROSSREFS Apart from leading term, same as A108100. Cf. A206399. Sequence in context: A020495 A155486 A225276 * A007584 A218329 A009924 Adjacent sequences:  A008524 A008525 A008526 * A008528 A008529 A008530 KEYWORD nonn,easy AUTHOR 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.

Last modified January 16 15:53 EST 2019. Contains 319195 sequences. (Running on oeis4.)