a(n) is the permanent of the n X n matrix M(n) that is defined by M[i,j] = sigma(gcd(i,j)).

A359111

a(n) is the permanent of the n X n matrix M(n) that is defined by M[i,j] = sigma(gcd(i,j)).

Terms

    a(0) =1a(1) =1a(2) =4a(3) =22a(4) =266a(5) =2218a(6) =58100a(7) =644828a(8) =20949776a(9) =502226904a(10) =20622109728a(11) =339816568512

External references