Number of isomeric aza-benzenoids with four nitrogen atoms and n hexagons.

A121952

Number of isomeric aza-benzenoids with four nitrogen atoms and n hexagons.

Terms

    a(0) =3a(1) =22a(2) =194a(3) =1620a(4) =12982a(5) =98765a(6) =720519a(7) =5073805a(8) =34707100a(9) =231739037

External references