Not necessarily symmetric n X 3 crossword puzzle grids.

A034184

Not necessarily symmetric n X 3 crossword puzzle grids.

Terms

    a(0) =1a(1) =15a(2) =111a(3) =649a(4) =3495a(5) =18189a(6) =93231a(7) =474479a(8) =2406621a(9) =12187137a(10) =61668609a(11) =311938233a(12) =1577602849a(13) =7977940187a(14) =40342860995a(15) =204001993697

External references