Meandric numbers for a river crossing two perpendicular roads at n points, beginning in the (-,-) quadrant and ending in any quadrant.
A076907
Meandric numbers for a river crossing two perpendicular roads at n points, beginning in the (-,-) quadrant and ending in any quadrant.
Terms
- a(0) =2a(1) =2a(2) =6a(3) =10a(4) =32a(5) =62a(6) =210a(7) =436a(8) =1540a(9) =3346a(10) =12192a(11) =27344a(12) =102054a(13) =234388a(14) =891574a(15) =2085940a(16) =8057844a(17) =19134786a(18) =74864648a(19) =179968564a(20) =711708544
External references
- oeis: A076907