%I A007202 M4899
%S A007202 1,13,57,153,323,587,967,1483,2157,3009,4061,5333,6847,8623,10683,
%T A007202 13047,15737,18773,22177,25969,30171,34803,39887,45443,51493,58057,
%U A007202 65157,72813,81047,89879,99331,109423,120177,131613,143753,156617
%N A007202 Crystal ball sequence for hexagonal close-packing.
%D A007202 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%H A007202 T. D. Noe, <a href="b007202.txt">Table of n, a(n) for n=0..1000</a>
%H A007202 <a href="Sindx_Cor.html#crystal_ball">Index entries for crystal ball 
               sequences</a>
%H A007202 J. H. Conway and N. J. A. Sloane, Low-Dimensional Lattices VII: Coordination 
               Sequences, Proc. Royal Soc. London, A453 (1997), 2369-2389 (<a href="http:/
               /www.research.att.com/~njas/doc/ldl7.txt">Abstract</a>, <a href="http:/
               /www.research.att.com/~njas/doc/ldl7.pdf">pdf</a>, <a href="http:/
               /www.research.att.com/~njas/doc/ldl7.ps">ps</a>).
%F A007202 Nearest integer to (7/8)*( (n+1)^4 - n^4 ).
%p A007202 G.f.: (x^4+10*x^3+20*x^2+10*x+1)/(x-1)^4/(x+1).
%o A007202 (PARI) j=[]; for(n=0,75,j=concat(j,round((7/8)*((n+1)^4-n^4)))); j
%Y A007202 Sequence in context: A005902 A051798 A061161 this_sequence A147384 A147011 
               A147019
%Y A007202 Adjacent sequences: A007199 A007200 A007201 this_sequence A007203 A007204 
               A007205
%K A007202 nonn,easy,nice
%O A007202 0,2
%A A007202 N. J. A. Sloane (njas(AT)research.att.com) and J. H. Conway (conway(AT)math.princeton.edu)
%E A007202 More terms from Jason Earls (zevi_35711(AT)yahoo.com), Jul 14 2001