Number of ordered finite sequences a_1 <= a_2 <= ... <= a_n of length n of positive integers less than or equal to n whose product is n! and whose sum is n * (n + 1) / 2.
A119551
Number of ordered finite sequences a_1 <= a_2 <= ... <= a_n of length n of positive integers less than or equal to n whose product is n! and whose sum is n * (n + 1) / 2.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =1a(9) =2a(10) =6a(11) =6a(12) =22a(13) =22a(14) =60a(15) =159a(16) =377a(17) =377a(18) =1007a(19) =1007a(20) =2867a(21) =8147a(22) =22403a(23) =22403a(24) =67808a(25) =176128a(26) =495053a(27) =1362240a(28) =4210266a(29) =4210266
External references
- oeis: A119551