Sum of the sizes of the fourth blocks in all set partitions of {1,2,...,n}.

A270496

Sum of the sizes of the fourth blocks in all set partitions of {1,2,...,n}.

Terms

    a(0) =1a(1) =12a(2) =97a(3) =675a(4) =4418a(5) =28396a(6) =183615a(7) =1211936a(8) =8237223a(9) =57944187a(10) =422950882a(11) =3206531728a(12) =25247250641a(13) =206313943476

External references