Number of set partitions T'_t(n) of {1,2,...,t} into exactly n parts, with an even number of elements in each part distinguished by marks, and such that no part contains both 1 and t with 1 unmarked or both i and i+1 with i+1 unmarked for some i with 1 <= i < t; triangle T'_t(n), t>=0, 0<=n<=t, read by rows.
A261318
Number of set partitions T'_t(n) of {1,2,...,t} into exactly n parts, with an even number of elements in each part distinguished by marks, and such that no part contains both 1 and t with 1 unmarked or both i and i+1 with i+1 unmarked for some i with 1 <= i < t; triangle T'_t(n), t>=0, 0<=n<=t, read by rows.
Terms
- a(0) =1a(1) =0a(2) =0a(3) =0a(4) =1a(5) =1a(6) =0a(7) =0a(8) =3a(9) =1a(10) =0a(11) =1a(12) =10a(13) =8a(14) =1a(15) =0a(16) =0a(17) =30a(18) =50a(19) =15a(20) =1a(21) =0a(22) =1a(23) =91a(24) =280a(25) =155a(26) =24a(27) =1a(28) =0a(29) =0
External references
- oeis: A261318