A086875 Sum of rank(M) over all n X n matrices over Z with all entries zero or one.

1, 21, 1147, 211965, 143331811, 366753209781

Offset: 1

Author

Tom Womack (tom(AT)womack.net), Aug 21 2003

Keywords

• hard
• more
• nonn

Comments

The unlikely-looking symbol "+:=" in the MAGMA code is in fact correct. - N. J. A. Sloane, Feb 02 2009

Crossrefs

Cf. A064230.

Programs

Magma

for a in [1..5] do b := 0; for c in CartesianPower([0,1], a^2) do b +:= Rank(Matrix(a, a, [aa : aa in c])); end for; print b; end for;

Formula

a(n) = Sum_{k=1..n} k * A064230(n,k). - Alois P. Heinz, Jun 18 2022

Extensions

a(6) from Alois P. Heinz, Jun 18 2022