Number of successions in all the permutations p of [n] such that p(1)=1 and having no 3-sequences. A succession of a permutation p is a position i such that p(i +1) - p(i) = 1.
A180187
Number of successions in all the permutations p of [n] such that p(1)=1 and having no 3-sequences. A succession of a permutation p is a position i such that p(i +1) - p(i) = 1.
Terms
- a(0) =0a(1) =1a(2) =0a(3) =3a(4) =14a(5) =72a(6) =468a(7) =3453a(8) =28782a(9) =267831a(10) =2752828a(11) =30984336a(12) =379125192a(13) =5011756625a(14) =71190365580
External references
- oeis: A180187