%I A024490
%S A024490 1,2,3,4,6,10,17,28,45,72,116,188,305,494,799,1292,2090,3382,5473,8856,
%T A024490 14329,23184,37512,60696,98209,158906,257115,416020,673134,1089154,1762289,
%U A024490 2851444,4613733,7465176,12078908,19544084,31622993,51167078,82790071
%N A024490 a(n) = C(n-1,1) + C(n-3,3) + ... + C(n-2m-1,2m+1), where m = floor((n-2)/
               4).
%C A024490 Essentially both the first difference sequence and partial sum of A005252, 
               so its own shifted second difference and indeed virtually the same 
               as A005252, so close to being its own shifted first difference.
%H A024490 T. D. Noe, <a href="b024490.txt">Table of n, a(n) for n=2..502</a>
%H A024490 INRIA Algorithms Project, <a href="http://algo.inria.fr/bin/encyclopedia?Search=ECSnb&argsearch=886">
               Encyclopedia of Combinatorial Structures 886</a>
%F A024490 2a(n)=F(n+1)-A010892(n), F(n) = n-th Fibonacci number. - Mario Catalani 
               (mario.catalani(AT)unito.it), Jan 08 2003
%F A024490 a(n)=sum{k=0..n, Fib(k+1)2sin(pi(n-k)/3+pi/3)/sqrt(3) } - Paul Barry 
               (pbarry(AT)wit.ie), May 18 2004
%F A024490 G.f.: -1/((x^2+x-1)(x^2-x+1)) - Jon Perry (perry(AT)globalnet.co.uk), 
               Jun 22 2004
%F A024490 a(n)=sum{k=0..floor(n/2), C(n-k+1,k+1)*(1+(-1)^k)/2}; - Paul Barry (pbarry(AT)wit.ie), 
               Jul 05 2007
%Y A024490 a(n)=A000045(n+1)-A005252(n).
%Y A024490 Cf. A010892.
%Y A024490 Sequence in context: A026502 A060163 A106511 this_sequence A056469 A004047 
               A093912
%Y A024490 Adjacent sequences: A024487 A024488 A024489 this_sequence A024491 A024492 
               A024493
%K A024490 nonn
%O A024490 2,2
%A A024490 Clark Kimberling (ck6(AT)evansville.edu)
%E A024490 Additional comments from Henry Bottomley (se16(AT)btinternet.com), Apr 
               07 2000
%E A024490 Corrected by Mario Catalani (mario.catalani(AT)unito.it), Jan 08 2003
%E A024490 Further corrections from Hugo van der Sanden (hv(AT)crypt.org), Oct 05 
               2006