Number of matchings in graph C_{3} X P_{n}.

Terms

a(0) =1a(1) =4a(2) =32a(3) =228a(4) =1655a(5) =11978a(6) =86731a(7) =627960a(8) =4546684a(9) =32919766a(10) =238352021a(11) =1725762060a(12) =12495193865a(13) =90470101964a(14) =655039004548