Number of ways to stack n triangles symmetrically (pointing upwards or downwards depending on row parity).
A316585
Number of ways to stack n triangles symmetrically (pointing upwards or downwards depending on row parity).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =2a(5) =3a(6) =3a(7) =6a(8) =7a(9) =12a(10) =12a(11) =21a(12) =23a(13) =39a(14) =43a(15) =74a(16) =81a(17) =138a(18) =151a(19) =257a(20) =281a(21) =479a(22) =525a(23) =895a(24) =981a(25) =1671a(26) =1830a(27) =3116a(28) =3414a(29) =5813
External references
- oeis: A316585