Triangle read by rows: T(n,k) is the number of chains of length k in the poset of all arithmetic progressions contained in {1,...,n} of length in the range [1..n-1], ordered by inclusion.
A347580
Triangle read by rows: T(n,k) is the number of chains of length k in the poset of all arithmetic progressions contained in {1,...,n} of length in the range [1..n-1], ordered by inclusion.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =1a(4) =6a(5) =6a(6) =1a(7) =12a(8) =24a(9) =12a(10) =1a(11) =21a(12) =68a(13) =72a(14) =24a(15) =1a(16) =32a(17) =144a(18) =244a(19) =180a(20) =48a(21) =1a(22) =47a(23) =283a(24) =666a(25) =764a(26) =432a(27) =96a(28) =1a(29) =64
External references
- oeis: A347580