%I #8 Dec 15 2024 12:11:20
%S 0,0,1,2,8,11,14,15,20
%N a(n) is the exponent of 2 in the denominator of the probability P(n) of the occurrence of a 3-dimensional self-trapping walk of length n.
%D See under A077818.
%F P(n) = A077818(n) / ( 5^(n-1) * 3^A077819(n) * 2^a(n) ).
%e See under A077818.
%Y Cf. A077818, A077819, A377161, A377162, A378903.
%K nonn,frac,more
%O 11,4
%A _Hugo Pfoertner_, Nov 17 2002