a(n) = Sum_{k = 0..n} C(n,k)^7.A182421a(n) = Sum_{k = 0..n} C(n,k)^7.Terms a(0) =1a(1) =2a(2) =130a(3) =4376a(4) =312706a(5) =20156252a(6) =1622278624a(7) =132282417920External referencesoeis: A182421