%I #3 Jul 25 2018 21:12:26
%S 6,30,140,631,2786,12136,52368,224406,956516,4060038,17175132,
%T 72454075,304941386,1280898304,5371301504,22491017758,94055344244,
%U 392888085100,1639534704632,6835739258998,28477594607348,118551827347576
%N a(n) = A128941(n) + 2.
%Y Cf. A128941.
%K nonn
%O 0,1
%A Lyle Ramshaw (lyle.ramshaw(AT)hp.com), Apr 08 2008