Weighted count of equivalence classes of words w of length n+1 over {a, b, c, d, A, *} having exactly n letters, exactly one *, an even number of lowercase a's, and weight (-1)^(A(w)), where A(w) is the number of uppercase letters A.

A390529

Weighted count of equivalence classes of words w of length n+1 over {a, b, c, d, A, *} having exactly n letters, exactly one *, an even number of lowercase a's, and weight (-1)^(A(w)), where A(w) is the number of uppercase letters A.

Terms

    a(0) =1a(1) =5a(2) =22a(3) =95a(4) =406a(5) =1715a(6) =7162a(7) =29615a(8) =121486a(9) =495275a(10) =2009602a(11) =8124935a(12) =32761366a(13) =131834435a(14) =529712842a(15) =2125993055a(16) =8525430046a(17) =34166159195a(18) =136858084882a(19) =548012945975

External references