Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #21 Dec 27 2018 08:26:22
%S 1,13,19,43,55,79,87,135,141,177,201,225,249,321,321,369,381,429,459,
%T 531,555,603,627,675,683,767,791,887,935,959,959,1055,1061,1157,1205,
%U 1253,1289,1409,1433,1481,1505,1553,1601,1721,1745,1865,1865,1961,1985,2093,2123
%N Sizes of successive clusters in f.c.c. lattice centered at a lattice point.
%D N. J. A. Sloane and B. K. Teo, Theta series and magic numbers for close-packed spherical clusters, J. Chem. Phys. 83 (1985) 6520-6534.
%H N. J. A. Sloane, <a href="/A119869/b119869.txt">Table of n, a(n) for n = 0..9999</a>
%H Paul Bourke, <a href="http://paulbourke.net/geometry/waterman/">Waterman Polyhedra.</a>
%H Paul Bourke, <a href="http://paulbourke.net/geometry/waterman/gen/">On-line generator</a>
%H Martin Kraus, <a href="http://www.martin-kraus.org/LiveGraphics3D">Live Graphics3d</a>
%H Mirek Majewski, <a href="http://www.mupad.com/mathpad/2006/majewski/">Dedicated commands in MuPAD</a>
%H Wouter Meeussen, <a href="http://users.pandora.be/Wouter.Meeussen/ConvexHull3D.m">ConvexHull3D package & demo-file.</a>
%H Mark Newbold, <a href="http://dogfeathers.com/java/ccppoly.html">Waterman Polyhedra.</a> CCPOLY Java Applet.
%H Steve Waterman, <a href="http://watermanpolyhedron.com/watermanpolyhedra1.html">Waterman Polyhedron.</a>
%H Steve Waterman, <a href="http://watermanpolyhedron.com/MISSING.html">Missing numbers formula</a>
%F Partial sums of A004015, which has an explicit generating function.
%p maxd:=20001: read format: temp0:=trunc(evalf(sqrt(maxd)))+2: a:=0: for i from -temp0 to temp0 do a:=a+q^( (i+1/2)^2): od: th2:=series(a,q,maxd): a:=0: for i from -temp0 to temp0 do a:=a+q^(i^2): od: th3:=series(a,q,maxd): th4:=series(subs(q=-q,th3),q,maxd):
%p t1:=series((th3^3+th4^3)/2,q,maxd): t1:=series(subs(q=sqrt(q),t1),q,floor(maxd/2)): t2:=seriestolist(t1): t4:=0; for n from 1 to nops(t2) do t4:=t4+t2[n]; lprint(n-1, t4); od: # _N. J. A. Sloane_, Aug 09 2006
%t a[n_] := Sum[SquaresR[3, 2k], {k, 0, n}]; Table[a[n], {n, 0, 50}] (* _Jean-François Alcover_, Jul 12 2012, after formula *)
%t Accumulate[SquaresR[3,2*Range[0,70]]] (* _Harvey P. Dale_, Jun 01 2015 *)
%Y Cf. A004015, A004215, A055039.
%Y Cf. A055039 [missing polyhedra]. Properties of Waterman polyhedra: A119870 [vertices], A119871 [faces], A119872 [edges], A119873 [volume]. Waterman polyhedra with different centers: A119874, A119875, A119876, A119877, A119878.
%K nonn,nice
%O 0,2
%A _Hugo Pfoertner_, May 26 2006
%E Edited by _N. J. A. Sloane_, Aug 09 2006
%E Additional links from Steve Waterman, Nov 26 2006