The number of right-crucial (with respect to squares) permutations of 1,...,n.

A221990

The number of right-crucial (with respect to squares) permutations of 1,...,n.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =60a(7) =140a(8) =518a(9) =1444a(10) =8556a(11) =31992a(12) =220456a(13) =984208a(14) =7453080a(15) =39692800a(16) =289981136a(17) =1467791790a(18) =14316379108a(19) =86001855074a(20) =949804475890

External references