Number of permutations p of [n] such that 0p has a nonincreasing jump sequence beginning with three.

A292169

Number of permutations p of [n] such that 0p has a nonincreasing jump sequence beginning with three.

Terms

    a(0) =2a(1) =5a(2) =12a(3) =36a(4) =81a(5) =174a(6) =413a(7) =889a(8) =1870a(9) =4031a(10) =8490a(11) =17580a(12) =36647a(13) =75801a(14) =154676a(15) =316873a(16) =646614a(17) =1309277a(18) =2653548a(19) =5358828a(20) =10786403a(21) =21697201a(22) =43539382a(23) =87208388a(24) =174392929a(25) =348359875a(26) =694913277a(27) =1384281163a(28) =2755398784a(29) =5476741024

External references