Number of rooted toroidal maps with 4 faces and n vertices and without separating cycles or isthmuses.
A006424
Number of rooted toroidal maps with 4 faces and n vertices and without separating cycles or isthmuses.
Terms
- a(0) =20a(1) =831a(2) =12656a(3) =109075a(4) =648792a(5) =2978245a(6) =11293436a(7) =36973989a(8) =107727724a(9) =285451894a(10) =699013380a(11) =1601397330a(12) =3465135024a(13) =7135903782a(14) =14072047976a(15) =26707904230a(16) =48991682628a(17) =87164772761a(18) =150869282184a(19) =254695011933a(20) =420306632200a(21) =679327313795
External references
- oeis: A006424