%I #2 Mar 30 2012 18:53:09
%S 0,4,8,13,20,30,46,72,116,191,320,542,924,1580,2704,4625,7900,13470,
%T 22922,38928,65980,111619,188488,317758,534840,898900,1508696,2528917,
%U 4233956,7080606,11828710,19741272,32916164,54835655,91276304
%N A008585+A029907.
%Y Cf. A008585, A029907, (1-((-1)^a(n+4)))/2 = A172051.
%K nonn
%O 0,2
%A _Mats Granvik_, Jan 24 2010